I cannot wrap my head around how to play Atilla (in battles), and the game looks like ass.
I know I'm 3 months late to this, but fuck it. Plus it's gonna be helpful for anyone who wants to play Attila in the future.
Here's what you want to do in Attila:
1) Get a bunch of cav
2) Snipe the enemy general ASAP
3) ???
4) MASS CHAIN ROUT
General sniping is fucking devastating in Attila, it turns battles from a slow, unit stat-based Rome 2 slugfest to a chain rout party similar to the classic titles like Rome 1 and Medieval 2. No joke, you can often see the entire enemy army rout just 10-30 seconds after you snipe the general, then you quickly need to cause a morale shock by charging a mass of units in the back with pretty much anything, even if it's pure gutter trash like the Nordic Band.
Cavalry is fucking king in Attila, just like in Medieval 2. Infantry is really just there to be a wall which is why you should only have defensively-minded infantry in your armies, offensively-minded infantry is often fucking trash unless they're something like Huscarls, Hetaireia Guard or Athar's Chosen because they have an obscene charge bonus. Plus contrary to what you'd think, Germanics and Nordics have much more cost-effective melee cav than the nomads. Sure their tier 1 Germanic Mounted Warband/Nordic Mounted Raiders are ass but once they get upgraded to Germanic Horsemen/Nordic Horse Raiders you'll be surprised at how much work they can get done. Hell, their tier 1 melee cav being shit doesn't mean that they're useless, for example that one garrison unit of Scout Equites you get are the fucking MVPs of the WRE and ERE campaigns with how much work they get done in siege defenses if you know how to utilize them, despite them probably being the weakest melee cav unit in the game. On the field where you'll be fighting most of your battles (unless you choose to suffer as the WRE or ERE that is), you just want to do hit and run tactics with your cav. Just have small groups of 2 cav units run around enemy lines, then when an infantry unit gets too separated from the rest of the army do a horse sandwich, you'll take minimal casualties. Also always have one 2 unit group run around the back since the AI loves hanging back their general for easy sniping. You can beat 2 full stacks of Comitatensis Spears with just mediocre micro skills, an army of 1 Alani Noble general and 10-12 lowly Alani Cavalry Warriors. Cavalry is just that powerful in Attila.
When it comes to non-cav, as I said you want infantry that is on the more defensive side to hold the line while the cav does all the work, there are a few exceptions though, those are shock infantry that I mentioned earlier and some units like the Hun Uar Warriors which for some reason just completely devastate most other infantry units in the game. The only other offensively-minded infantry that I think are decent are the Gothic Warband, but they fall off quickly after the early game. When it comes to ranged units they seem really underpowered across the board except if they're horse archers or crossbowmen. Crossbows are really powerful in the game both in field battles and especially in sieges. You put a unit of crossbows on a barricade, have them hold fire and order them to shoot when an enemy unit gets close - that enemy unit gets devastated in just 1-2 volleys and barricades make them shoot ridiculously fast. Germanic Archers and Elite Germanic Archers are also notable for having 200 range. Slavic Archers and Slavic Hunters also due to how balanced poison is and that's why you want to play the Slavic factions completely differently from other factions, but that's a story for another day. For sieges you also obviously want onagers. Large onagers can also devastate the Hun doom stacks that you'll face in the late game if you put the army in a fort and then let the Hun stacks crash into them. The regular onager should only be used to destroy towers and collapse walls since they can't really do anything against regular units.