yeah man its a glitch in the game... but it has nothing to do with who you created and singed..
i use the giants and default rosters they are about a 72 rated team but then i moved up Brandon Jacobs from 3rd string to second string behind tiki on the depth chart and mind it that he is rated lower then cloud who was the second stringer.. after i did this small depth chart adjustment my team went from 72 to 86 overall for that one move that did not even affect the starters... so its a glitch
and the worst part is that when you donwload the new rosters on xbox live to play the giants are 72 but when you save them to your off line play and then make the depth chart change and play an off-line game the giants are 86 and then you go straight to on-line from there without turning the game off the giants on line will be 86 also...