If you and your friend believe the 1911 is a superior platform, then I wouldn't feel bad for moving him towards it. Just realize, there is a certain amount of practice is necessary when changing up. I would make sure your friend realizes he needs to get repetitions with the mechanics of the gun, like using the manual safety, in order to overcome the training he has done with his Glock. Same would be true of any changes in the holster that would effect releasing the gun.
I don't make jokes, I just watch the government and report the facts. -Will Rogers
An appeaser is one who feeds a crocodile, hoping it will eat him last. -Winston Churchill