While this could be true I think people forget how much time it actually takes. 35 min halves 10 min halftime = 1:20 plus warmup and team meeting after 2:30 now drive to next game 3:00. So two teams playing in two different tournaments at different fields with a perfect schedule is 12 hours.
Coaches who schedule two teams in different tournaments the same weekend are being discourteous to both teams. Conflicts during the league season are almost unavoidable, however, unless all of a coach's teams play at the same venue.