Absolute skills

It's pointless to focus on Creature Ability (CA) (in my opinion). If you play on Small or Medium maps, you'll spend a lot of time leveling up to level 23 (25), and you'll just get killed before you can do anything. In my opinion, the best CA is for Dwarves and Elves. You can, of course, make it work for the Undead, but sometimes it can be completely useless (for example, against Mages (in my opinion)). I don't level up Dark Elves with their Vision ability. My Mages usually focus on casting spells if it works. Humans are just bad; I never level them up. I don't have much experience with Barbarians yet. But in general, it depends on the map you're playing on. If it's a small or medium map, as I said, CA is pointless. On larger maps, they can sometimes be useless too.