Mages should definitely be targeted by Archers first.
Djinn, with their health, are easily defeated even by Dancers.
Nymphs should preferably wait a bit to heal the Ents.
Symbiosis is also good because sometimes you have to spend an entire turn to finish off the remaining Nymphs, because there will be a symbiosis, and you will have to kill them again.
In Blood, I think you should take Titans, Golems, and Gargoyles, as they are very durable, and this is a good support for the Mage with his spells.