New Strategy: Civil Protector

A strategy based around militia. The name "Civil Protector" comes from the real life use for militia, to protect a community or village.

Stats:
+3 attack, +2 defence (+3 against tanks and infantry) for militia
+1 attack, +3 defence and +5 critical hit chance for marines
+20 cost, -2 attack for all air & sea units
+1 defence, +10 cost for Infantry.

I see it as a bit OP, please tell me how it can be nerfed.

Sorry, but this is basically a GW with militia having 9 defence, and no marine cost boost. I don't really see a point in the idea of it, but if you can convince me otherwise...