You would definitely want more games in division, though I think you have to drop much more of the interleague schedule if you had 4 8-team divisions.
One might also want to play 13 games in division. One of the things MLB did with the current schedule is have 13 games in division. I assume they want this so there are always head to head tie-breakers if there is a tie in a division. Now there are only 64 games against the other divisions, so only 4 of those 10 teams get 7 games that can help with wild card ties.
If they want a balanced schedule I guess you have to go to 9 games in division (63). Then you have 48 (16x3) against the other league and 51 against the other 8 team division (6/7). Not ideal, but certainly doable.