cpu teams are preset and dont change at all. If you create a player and dont choose him for your team, he goes unused. If you pick a player that is on a cpu preset team, he will be on both teams.
If they want the cpu to be preset for exhibition games i am fine with that. But i feel they really should have made them replace a player in season mode if you choose the same player. If you choose Walter Payton, the cpu team should then choose another gold RB that is unused, including created gold RB's. It would have added a lot more variety to the season mode, getting to play against created legends and such...and not have to see walter payton from team X leading the league in rushing, and #2 from your team.
And yes give us more than 20 caps. let the file grow as big as your hard drive has space. or have 1 file for each player and save as many as you have room for.
a little off topic but that would come in handy for all other sports games. in NBA 2k7 i created dee brown on the jazz. each 2k roster update i downloaded, he was not on the jazz roster. so i had to go and create him all over, i had to do it 3 or 4 times. why cant i save him as a created player file, if he isnt in the roster update, load my cap file and get him on the roster? I wont have to create him over and over when he isnt in the updates, and i can just delete the cap file when/if he finally ever makes it into their updates?