Ok, let me ask it this way...
Assume you were in the championship game of the GenCon tournament and your opponent used multiple common cards because he believes it to be lucky to do so. You kill one of his 8 rats and he puts the rat on the same card that has an order marker. When he reveals his order marker and goes to move the rats, would you let him move a full squad?
Common Sense says he gets to move 4 rats...
WotC ruling says he screwed up and can only move 3...
You say that he incorrectly played the commons in the first place because we all know that you should only bring one card... even though the rules say it's fine to do otherwise. Therefore you would enforce the WotC ruling and limit his movement to 3 rats. Right???
Naw, I don't think I would.