Well, I would counter argue that other teams, ie., real football organizations do this all the time. If a player or player(s) are struggling or the line just isn't performing as a whole, other teams will shuffle existing lineup or bring someone off the bench. In fact, most teams start putting players on notice much earlier than we do. They are professionals. If they can't deal with the expectation they have to perform or run the risk of replacement, they are soft and that may be part of the issue to begin with.
No one is talking about occassional reps. We are talking about sustained level.
As this post was specifically about the RT, let's discuss. I have been a Steele supporter even though I have acknowledged his limitations especially post injury. They saw his play last year, offseason & now are in the 11th week of the season. They should have already been signaling to him that they were looking to make a change. Physically, he just can't deal with the speed \ lateral agility needed. If we hadn't drafted Booker, I would propose sliding him to RG & letting Thomas play RT. There isn't any reason not to try something different.