The Lakers this year have been better when Lebron is not in the game.
Now for the Lakers and Lebron it could be that their starting lineup is simply not as good as other starting lineups who they play against. So the Lakers are winning with depth. Their 6-9 is better than other guys 6-9.
The problem is you can't do that with Demin unless you are saying that the teams we face have better backup units than starters.
So I assume you are going to ask me if I think Egor has been better than Richie as he has a better plus mins. The answer is no. Richie helps boost Demin but gets weighed down a bit in also playing with the 2nd unit who's plus minus is not near as high.
But that still doesn't make sense that Demin has a higher plus minus than those he plays with. It is because when he is in the game BYU is at its very best. I'm sorry you can't see it (and yes he has had some struggles).