Wyverns

I like Ogres for their appetite and Demons for their impressive appearance. But generally, I don't use them much. I'd rather have 2 stacks of Shamans.

Imagine we're in a duel, you're an Orc and I'm an Orc. Our stats, skills, and army size are roughly the same. The only difference is that you have 2 stacks of 50 Shamans each, while I have one stack of 100 Shamans and 40 Wyverns. So, who's stronger?
Wyverns don't have Blood Fury, but their stats are decent. All Orcish creatures, except Cyclops and Wyverns, have lower stats than creatures from other factions. This is compensated by Blood Fury, which, in addition to increasing survivability, also significantly increases attack/defense and grants new abilities (each creature has its own bonuses from Blood Fury).
So, it doesn't make sense to consider them useless; their useful qualities have already been mentioned above. And to say that they are bad just because they are killed quickly... that's not very serious. It seems to you that they are quickly defeated because everyone else has Blood Fury. If Wyverns were in another faction, you wouldn't think so. But personally, they are rarely defeated in my games (except in final battles).
And one more thing, it's very important to consume the corpses of Angels and Paladins if the Knight has the "Guardian Angel" skill. In this case, they play a key role.