Community Mod, if the change is approved by the main balancing/gameplay team.
Otherwise, other mod or as an addition to "Two-gendered Citizen" mod.
It would encourage earlier raids, as CS are now bad at collecting wood so you are forced to make pure eco citizens (who are weaker) if you want to boom. You'd still have to mix eco and military units if you want to play it safe, it's just that now you are hurting yourself economically while doing so (as you should).