I played a bit more... Griffons are not as effective without an attack.
Angels can no longer resurrect (or maybe I just didn't figure it out).
But their archers are better than crossbowmen and regular archers.
In general, they could have been given a castle, because as it says on the expansion pack: 2 FULL-FLEDGED factions.
This faction is not full-fledged. IMHO.