Yes, the factions that lack cavalry (Yetia, Abominia, Terrans, Atraco, Scorp) are going to have more powerful infantry. They will have higher attack than other factions using the same weapons. However, factions such as Yetia, Abominia, and Atraco also lack armor and will be more vulnerable to arrows. They will have some protection from fur/thick skin, but this is not as good as mail/plate armor. The reptilian scales of Sauria won't really offer any extra protection, but most of their units are wearing armor anyways.