I'm sorry, but this is simple thinking. Lamson has practiced the offense for two years, has worked with these teammates, has hopefully developed some chemistry with them, even those on the 2nd team. Because eventually, 2nd teamers become starters,
Bringing in a completely new guy, with no chemistry or history with the other players, it makes him a carpet bagger on his new team. This is a big part of why a lot of transfers don't do as well at their next location. You're just parachuting into a group of players who already think of themselves as "the team".