If the five institutions play a round robin, you have eight "league games" (four home/four away) for everyone minus SFA & SHSU which is four home/three away/one neutral or three home/four away/one neutral. You can likely play those games over the final eight or nine weeks of the season (based on when previously scheduled OOC games are) and then play three OOC games (which most of these schools already have).

Of note, both SFA & SHSU have two OOC home games in '21

Lamar has two road, one home (albeit home one is Tarleton) and ACU has two road (one of which is Southern Utah, interestingly)