This is a generalisation but umpires don't care about defensive position with the exception of if it impacts the DH spot. So if there is a pitching change and the pitcher goes to RF and the RF goes to LF and the LF goes to the mound - Blue doesn't realy care about that becasue the batting order and substitution pattern is undisturbed.
Beyond the DH spot what umpires do try to manage is the reentry of players and curtesy runners to make sure that the substitution rules are followed.
I also suspect that most of the guys calling the games aren't worried about the statistics but are worried about making sure both sides know what the batting order is.