Autoresolve is dependent on unit stats, but unit HP heavily influences results. It's been this way for a very long time (since RTW & M2TW). Sieges, and forts have autoresolve calculated differently since M2TW. It's harder to attack a city than a field battle normally in autoresolve.


I don't think much matters aside from base stats (Attack, Defense, HP). Morale probably doesn't factor in much, if at all. The battles aren't resolved in stages, it is all just calculated all at once (far as I understand). There is no skirmishing phase where missile units get damage in, for example, it just all globs together and whatever army has the most overall stats wins. Then units are randomly affected by percentage based casualties.

Close victory? Then most units of yours have 1/4 HP remaining.