Nagas can be quite good if used with magic)). He-he... although they are also weak (like the Crusaders) in the original game... they don't have a circular attack, like in Equilibris)).
Vampires... like Nagas, but they also regenerate health. Quite a cheat, with their retaliatory attacks, flying ability, and undead nature)).
Ogres... I agree, they are weak in the original game, but they can be decent as additional infantry)).
And Ifrits also kill well. Maybe like Horrors, but they also take enemies with them using their shield)).
Djinn don't need stats; the main thing is that they have mana)).