say if A-B is the route you want to fly, B-C, A-D are 2 short routes to fill the hours
plane 1
day 1: A-B, B-C, C-B
day 2: B-C, C-B, B-A
day 3: A-B, B-C, C-B
day 4: B-C, C-B, A-B
plane 2
day 1: B-A, A-D, D-A
day 2: A-D, D-A, A-B
day 3: B-A, A-D, D-A
day 4: A-D, D-A, A-B
or
day 1: B-C, C-B, B-A
day 2: A-B, B-C, C-B
day 3: B-C, C-B, A-B
day 4: A-B, B-C, C-B
Got it?
In the second ooption of plane 2, you would get what you want. It is just a matter of your interpretation.
As for the base, it really doesn't matter because the current system don't care if you get any maint in, as long as you pay up.