it seems to me that whoever gets glaives as their raider gets an advantage since glaives are cheaper. I got archer and I had a slower time getting mexes because of archer being costly and slower. Then once he got the advantage, he spammed moderators and rogues and I couldnt do anything.

how am I supposed to get ducks? this is arena mod and I dont remember ducks being available in that factory

Yeah, you are totally right that Glaives most likely are the best raiders in Arena. Although Scorchers do pretty well aswell killing mexes early.