Glad to hear that my schedules are of some use
If I understand you correctly, you have three divisions (of varying sizes) in a single league. To make one combined schedule, you can mash together a few of the schedules I've created into one file.
This really wouldn't be a difficult process, I can do it for you if you like. Could you please just tell me what the sizes of your divisions are, and which order they should be in? (i.e Div I has 6 teams, Div II has 8, etc)
Edit: could have read your comment more closely the first time. After a single, combined schedule is made, you wouldn't have to worry about the divisions being screwed up. The game only randomized the schedule
within divisions.