Okay, fine. However, the offense would almost certainly run at that lineup. Even in this hypothetical situation with roughly 2:00 left in the game and needing a TD to win, you could still put in a quick draw or two. That would indeed eat up some time, but if you had another play called and went immediately to the LOS and ran a quick pass, you could have a running play. The quick draw would almost certainly net 15-20 yards or so and possibly a lot more. The run defense would just be horrific with Cole at DT.
To be fair, I know that at one point Dallas was talking about moving Ellis to DT in sure passing situations, so this isn't unheard of. Still, I'd question the move and it wouldn't take offensive coordinators long to put in a couple of plays to make the defense rue the day they put a light DE at DT.
Maybe if Jim Johnson did it as a surprise every now and then. If he did it with any regularity, the offense would expose it big time.
JMO, of course.