By the time conference play comes around, the playing rotation will be pretty set. Even with all the bodies this year, I don't think the regular rotation goes beyond 8 or 9 guys. Obviously, circumstances like foul trouble can change that. So, the 10th-13th guys really won't matter that much. Who those last 3-4 guys are would likely change for different games...

If someone in the "top 13" gets injured, that opens up a spot for someone who hadn't been on the travelling.

Or, it could be matchup based... if you're playing a small team, more guards make the travelling squad and vice-versa.