I'm playing a game as doviello now, not using the duel/xp share exploit this time. Still rampaging all over the world.
I find the thing that's helped me most, is running undercouncil and upgrading slaves. The animals were nice, but mainly the "mark of.." promotions were useful. Actual animal spawning rarely was, except for one powerful wolf pack I got when only wolves were spawning.
Perhaps it has something to do with the poor capital location, and resulting bad production, but I found that I couldn't really build the dens fast enough for them to be useful.. Also, I think mammoths should be stronger, but come later. Str8 seems like a lot, but with no defensive bonuses, and a penalty to city attack, it's a lot less. Also, animals don't get any xp share experience, can't duel, and there doesn't seem to be any way to level them up outside of combat, so I found them overall inferior to footsoldiers. A lv4 Son of Asena is more useful than a lv1 mammoth rider I'd say, and I can get either without having to fight a single battle
Also, I began to regret building the stag copse after a while. Spells like haste, treetop defence, etc, are good, but you only need one unit in a stack to cast them. My stag spawn rates went through the roof, and I ended up with hundreds of the little buggers. Str 3, and not really good for much. I couldn't even seem to combine them into a Stag herd, which was disappointing consideringI could do the same with wolves. I also couldn't see any way to upgrade them to Elks. Perhaps it can be done through levelling, but getting xp for a str3 unit isn't easy beyond the first 100 turns or so.
I got the bear/lion/griffin things too late to be of much use, it seems. The build costs on them really are a bit much, especially with flavourmod's decision to dump me in an icy highland with not a single flat land or river in sight. I had to run a windmill economy for most of the game just to break even on food, and my capital grew VEEEERY slowly.
I will say though, that although I didn't get much use out of bears, the mark of the bear promo is quite useful, being that it's essentially free March. It also leads to Bear Kin after only combat III, which gives +1 str. Might be a bit powerful.
but only a select few of my units ever got the animal promos. 90% of my army now is battlemasters upgraded from slaves. It was the only thing that could provide the raw power and easy availability needed for my rampage across erebus. The animals were kind of left in the dust, except for one of the first wolves I ever got, later upgraded into a str10 Wolf pack with Empower V. That was mainly because of there being nothing but wolves early on. haven't managed to get such numbers of any specific animal since.
In general though, the mammoth spawn rate seems a little high. Mammoth riders certainly do look intimidating, but they were still disappointingly ineffective. I'd rather see mammoths made later, more powerful, and rarer.
It'd be nice if normal troops could go to where you've built the animal dens, and "bond" with the animals, to recieve the "mark of.." promotion. It's a bit limiting to only be able to get them from units built in those cities. And it means cramming them all into one city is the only way to get the full potential out of it.
Also, as an Aside, a notable bug.
It seems that the Doviello's +1
on ice also applies to hills, meaning that I get the same food output from ice hills and ice flatlands. however, it doesn't work with Ancient Forest. Although that gives +1 food in the tile, an ice hills tile with AF on it was still only giving 1 food. It worked on the flatlands though, but I just wonder if this is how it's supposed to work. Seems strange.
Means I'll still have to mess with it to import the camel icon, but that's something that's already there. 
from it too.
