[PvK]

Slime and Vine arrows are not so bad when they are hitting deadly enemies. Fir Bolg can be very good thugs. Couatl are good tough astral mages. Vine creatures (especially ogres) are very very good for the price - be patient and mass them. Mass Protection is pretty good. Relief can be a very good spell, since it allows much more casting of other spells. Water magic allows entering and attacking the water. Sea King's Court gives an instant tough amphibious army. Quickness, Frozen Heart, and various ice strike spells and eventually Murdering Winter, sword of swiftness, quick boots, clams, jade armor - not enough overpowered toys there?

As with all things, use them for what they are, not what you wish they were.