Basically, I think that every secondary postion shouldnt automatically be a ratings drop.
When center fielders get moved to the corners irl they generally grade out better defensively then in center, same with ss at 2b and 3rd basemen at 1st. If the opposite happens then the player usually grades out worse.
So my idea is that if i have a center fielder (ie. Ricky) and move him to his secondary position (LF) his defensive rstings should go up not down. If i have a right feilder (ie. Judge) and i move him to center then he should have the rating drop because he is playing a tougher position then his primary.