The game converts OOTP 9 leagues as good as possible. The examples stated that suddenly relievers in OOTP 9 start in OOTP 10 is not a relevant point, these pitchers could have been used as starters in OOTP 9 and they would have performed well of their ratings were good. OOTP 9 basically had an AI flaw in that it did not use these pitchers as starters even if they could start (on a 1-100 endurance scale anybody above 25 was able to start). OOTP 10 fixes this, leading to optimized rosters.
This works flawlessly in my opinion.
If anyone feels that this sevelery hinders the enjoyment of the game, contact
support@elicense.com for a refund request.