this also is a re ed claim
if hes a product of the east (implying the east has far less talent), then you have to take into account the fact that his supporting cast is less talented too. among the eastern conference teams, he had a very good supporting cast.
so if you wanna plug him into the west, you gotta plug him into a western team with a comparable level supporting cast for western conference teams. he should have one of the 2-3 best supporting casts in the west. so take this year for example, say you replace westbrook with lebron, and hes able to play with PG, shroeder, and Steven Adams. would they not dominate in the west too, aside from maybe GS?
he literally went from kyrie and love (a solid #2 & #3 option) to ingram and kuzma (a young, rather lousy #2 & #3 option)
he went to a tougher conference and has a worse supporting cast than he previously had. do we really expect him to be at the top of the conference in that situation?