Giving the Packers 10 more players is huge as it would be for any team that believes in developing their own talent. 10 more players gives you more to compete with, more pseudo live action.
53 roster, but 45 active ... someone explained this awhile back and it made sense. Sure as heck wish I remembered what it was cuz I'm back to thinking it's foolish.
Edit, it's to provide more competitive balance so one team doesn't hoard more players than the other. Basically it ensure that if you have 3 injured players of your 53, you have to trim to 45 as does the other team to help ensure both teams have the same amount of healthy players.