15 teams in a league and no interleague play means one team is inactive everyday. Due to travel issues one team would proabably be inactive for 3-4 days in a row. The HAL 9000 couldn't come up with a workable schedule under such restrictions.
Back when we played a balanced everybody complained because teams were playing the majority of their games outside the division.
If you want "fairness" expand to 32 teams with 8 teams per division and two divisions per league. Have a balanced 154 game schedule strictly within each division. The division winners will meet in a best of seven playoff series. The winners of the playoff series will meet in a best of seven "world series".
Buck O'Neil: The Monarch of Baseball