If every player was evaluated after starting 9 games as a rookie then the 90's team wouldn't have Nate Newton or Mark Tuinei.
The 70's and 80's teams wouldn't have HOFer Randy White who wore #54 because he was designated a LB. Randy did not become a perennial Pro Bowler until he was switched to his natural position of DT.
Did you know that Tyron Smith did not play LT his rookie season? Tyron was the #9 overall pick and first O-lineman taken in the draft.
Even Jason Garrett realized that you don't protect your QB's blind side with a rookie. Tryon played his rookie season as the RT. Doug Free was the LT that season and when it was over they switched sides.
So Guyton is mentally weak because someone else claims to have better knowledge of his injury and how his body reacts. This someone has determined that Guyton should be able to play through it.
He has surmised that playing Guyton couldn't possibly complicate the injury to the point of irreparable damage. And if this someone is wrong? What repercussions will this anonymous medical expert face?
We don't have all the information and some of the information that we have been given is deeply suspect. Let's not judge yet.