I wouldn't "try to leave them out". I'd either leave them out or include them, there is no "try".
And duh, if they are 13-0, they are in the playoff, no one would dispute that. I think it more likely they finish 9-3 than 13-0.
Haggling over minutiae at this point in poll rankings is just that, minutiae. Rank'em however you wish, it hardly matters, I do tend to vie for some consistency.
Discussing which teams have how much shot at the playoff is reasonable conversation.