Hmm. I don't know. It does reduce early strategies for the British by one, since you cannot tech the grenades. Not that they are much used, but I would love to see people experiment with them before teching. Would be interesting.
Although, with the carrier fuel removal, the increase in tech cost and grenades added atop it does make it an appealing change. Problem is: you may want to rush teching either way by placing a fuel cache down. Your change does not discourage that; it encourages it.
