Gremlins: Health(8), initiative(around 30), and for example magic defense;
Gargoyles: Health, initiative and speed(3);
Golems: speed(3+2), initiative(30+2), if playing as Razzak (the creator of golems) and upgrading "Golem March", then the golems will be absolutely unbearable, and also luck(4);
Mages: initiative, luck and magic resistance;
Djinn: speed, initiative, health/armor;
Rakshasas: speed, initiative and attack
Titans: initiative, luck and attack.
Magic resistance helps a lot if playing against Warlock; you can equip the entire army with it!