How to fight the Huns

Note that pretty much all of my Attila playthroughs are with Radious mod and that I play on normal difficulty (I myself want to enjoy the game, not be all sweaty, besides it can be super challenging even then...)

Also I played against Huns majorly as Sclavenians, but since I haven't really gotten to any Slavic-exclusive units (ie. Horse eaters, Poison Arrows etc.), it definitely shouldn't be a problem to use these tactics with any other faction.

Don't be scared to field basic teir 1 units! They are much stronger than you'd say! Besides I haven't seen Huns using even tier 2 units!

Let's start with very important, yet still optional (makes lotta sense, eh) preparations for battle.

First - go to your settings, click on Audio section and turn off the Music.
Then go to youtube and get some proper slavic music (pagan one, as we're pre-christian and pre-hardbass era). I highly recommend "Slavic Affairs" channel:

For in campaign map preparations: "Land of Gods" (https://www.youtube.com/watch?v=3g59-3qpbnw)
For defensive battle: "Slavic Pagan War Drums" or "This is Slavia" (https://www.youtube.com/watch?v=BYAZ5RZBMgk or https://www.youtube.com/watch?v=55tu3kTyHRU)
For offensive battle: "Wild Hunt" (Since you are going to hunt them pesky ♥♥♥♥♥♥♥♥♥♥♥♥!) (https://www.youtube.com/watch?v=g9kUpQ1GpOk)

Any Witcher battle music goes well too!

Let us start on campaign map, specifically in your city (that is possibly going to be attacked) building screen.

Make sure to have your main building ready - it is much easier to defend your city with levels 2+, but even basic level works well.
I highly recommend to get the Pastures building from farming tree - it gives you garrison of Slav Horse Raiders (Javelinmen), which can seriously help you out if the pesky ♥♥♥♥♥♥♥♥♥♥♥ bring catapults or any high threat ranged units.

Building an army
If you feel that a perticular city is going to get attacked and you don't have your primary army near, make sure to hire a new one and immediately get it into city.
What you want to recruit are definitely tons of spearmen (trust me) - get as many as you can. If you have more time, definitely invest in melee infantry (Slavic Axe Levies are well enough).
Other essential units should be given to you by your maing building (Garrison Armies).
Make sure to have your newly recruited army INSIDE of the city, as the Huns will make short work of your reinforcements.

Let's say ♥♥♥♥♥♥♥♥♥♥♥ came as usual with 15-20 units big horde. They prefer (and I've met only one of their hordes, which was different) to have at least half their army composed of various cavalry units. They are well going with quantity over quality scheme, so expect mainly tier 1 units (even in fairly later game, when i had full upgraded tier 2 armies, they still hit me up with basics)

Don't be scared by their Horsearchers! Archers generally suck in Attila, close to useless as they deal very low damage, no armor piercing and 95% of your targets have big shields (and most of your units do have fairly big shields)

Unit Layout
In my playthrough(s), Huns always attacked cities, which had a sort of a fortress protecting its main capture point (no, those were not province capitals, those were minor settlements in Gothiscandza, city of Budorgis and Oium) with 2 or 3 entrances - ideal.
Make sure plug those bottlenecks/chokepoints with spearmen in shieldwall (or what's it called), behind them your melee infantry (if possible, get them into shieldwall to minimize possible casualties from archers). Archers are going to cover them from walls.
Help yourself with barricades! (Sometimes you can even put them into the fortress entrances!) - Lead the enemy the way it suits you best. Important note: Cavalry can't break barricades!

Tactics
Very simple. The default combat AI is super stupid and will charge your spearmen with everything they got. The amazing advantages of the fortresses is that they are on hills, which neutralizes devastating cavalry charges and renders cavalry's strengths useless. What to do with the spearmen then is purely up to you - I "charge" with them into the enemy to use every man, but you can surely leave them in shieldwall as i surely has its advantages
Melee infantry - wait for enemies' charge, once they are stopped by your spearmen wall, charge in from the back. Don't worry - the cavalry has zero speed so they can't harm your non-spearmen units as much. The axemen are a lot of help, especially once the ♥♥♥♥♥♥♥♥♥♥ infantry arrives.
You now have almost all stone-paper-scissors advantages on your side - spearmen wrecking their cavalry, axe chewing through enemy infantry.
Now what with archers? That is up to you. The walls give them much needed advantage which they can utilize to avoid possible friendly fire. Be sure to set them to heavy shots though! (If you want them to do any damage at all!)

If you want to hunt them disgusting ♥♥♥♥♥♥♥♥♥♥♥ plundering your lands you justfully conquered or just want to finish up the survivors of recent defensive battle, make sure to have certain precautions. Don't worry, it is easier and simpler than you think!

Army composition
Simple enough, even the super basic 50/50 composition can give the Huns a hard time. Let's start with basic scheme you can wary: 10 infantry units (counting general for Slavs) and 10 cavalry skirmishers.

Infantry section
The general unit is OP straight from the start - very heavy axe infantry with big shields
Get tons of spearmen, majority if possible
Optionally get few units of melee infantry to help you out with their infantry
Also optional are some missile units, but those aren't very essential, as archers are close to useless. If you desperately want some though, get good javelinmen.

Cavalry
You guessed it - all of them horse javenlimen (Slavs don't even have any othe kinds of cavalry either)
Don't really bother with melee or shock cavalry - Huns are fast. Only when they can be useful is to pick on their archers or outflanking infantry. However, Huns don't usually have strong presence of ground units.
Horse Javelinmen, even the basic ones for Sclavenians, are extremely strong and versatile. The only downside, however, is their very low ammunition (round 7 javelins per soldier, which sucks). I found out javelins are generally much much better againts cavalry than arrows making these units absolute go-for against tthe Huns!

Offensive battles are much trickier than defensive one, no surprise, and every battle can be different.
I found fairly effenctive, yet very simple and basic scheme:

Make the offensive battle a defensive one.:
Use your infantry to take a strategically beneficial position (hills if possible, but don't worry, I found it works just as well on plains) - make a strong line of spearmen shieldwall with some units as backup and flank guards, melee infantry taking cover behind them (That is crucial! Your axemen don't stand a chance against cavalry charge!), if missiles units - as close to spearmen as possible, but still behind them (once there is a low cavalry threat and spearmen are engaged, you can retreat a bit with them or even flank the enemy to minimize friendly fire)

Now to the tactics themselves!
Use your cavalry to deal damage to their cavalry. Don't worry, even if the enemy has the skirmish mode on, the horse javelinmen still have bigger range, besides they can shoot while moving. Use your cavalry to guide the enemies' one to charge your spearmen - just "run away", the Huns will follow.
a) If you have time, go with your cavalry around your spearmen - the Huns go straight after your cavalry, they don't care about maneuvering, resulting in their charge straight into your prepared spearmen.
b) Stop with your cavalry close to your ranks, tell your spearmen to attack the coming Huns and then run away (with your cavalry) as close to enemies' impact as possible, resulting in your spearmen having a great chance of catching the enemy cavalry.

If it doesn't work at first, worry not, repeat. It is you, who has the control of the battlefield!

You can then don't whatever you want. Flank the enemy and finish them as quickly as possible.

Note: It may not work at first, as the horse archers would still be in skirmish mode, resulting in them keeping distance from your infantry. I highly recommend so to take your time - make them waste as many arrows as possible (and boi, do they have a lot), which shouldn't be much of a problem since they deal very very low damage and have high rate of fire.

Fighting ♥♥♥♥♥♥♥♥♥♥♥ isn't as scary and hard as you might think. Sure, if they come with 8 20-unit armies while you have barely 1, then, I admit, my guide might not work. However if you stay up north, therefore having to deal with regularly just 1 horde at a time, chance of winning go back up drastically.

I might've forgot something. If I come up with anything better, I'll make sure to update this guide!

Thank you for reading, make sure to rate up, so that not-so-experience players can see this and help them out with this pain in the ass that are the annoying ♥♥♥♥♥♥♥♥♥♥♥!