What John is saying is to add a day flight to EZE. Yes, this will decrease layover time down there, which CO cannot afford with its lack of widebody aircrafts.

But a early IAH departure and late arrivals mean little to no connection possibilites (except to the West Coast). They'll unlikely go this route. And even though many expects AA to apply for a day flight from MIA to EZE, in additional to the two night flights they already have, AA decides to a night flight from ORD instead.