Well, overriding the carpeter would imply that you cripple your possiblities only to get the reward. Since some carpeter victories come from cards like Gateway and others, which are very aimed at facility increasement, this would be very hard to pull of and still win.
I'm with DPsycho here, it would not bring any new edge to the game. What is possible instead is a card which gives a direct win when you got like 5 or more facilities than your opponent. Much like Outnumbered and Outmatched and others.
Also we had some topics where people had a small statement in the title and almost no words for why or when some options should be considered. This implies writing in full sentences and reasons why a change would be healthy for the game. Just bringing an idea without telling why it could be usefull doesn't really help the developement of this game.