not a solution but...
if you have the AI set to play potential over ability, it should prevent lineup/staff related issues related to this concern.
although, does this setting only affect setting lineups/staff or does it also influence AI MiL decisions? i don't believe the manual states this specifically from my memory. it may or may not alleviate all possible issues that might arise from "old" players clogging the system.
heh, i just called a 21 year old, old. funny stuff