When building an Explorer, at the stage that crews are deducted (a year before commissioning) there will be a vote to crew it with standard Starfleet or Explorer Corps, if you have sufficient Explorer Corps crew.
And to make sure I understand correctly how Explorer Corps crew works, currently the Academy is at:
Starfleet Academy:
Officers (O): 3.25pts (+1 Explorer Corps)
Enlisted Crew (E): 4.25pts (+1 Explorer Corps)
Science Techs (T): 3.25pts (+1 Explorer Corps)
Meaning that it gives us exactly 1 Explorer Officer Unit, 1 Explorer Enlisted Unit, and 1 Explorer Science Tech Unit per year? Will expanding the academy result in more explorers or only more regular crew?
If expanding the Academy won't help, then we'll need to preserve political will for using the option for:
Request
Temporary Explorer Corps Recruitment Drive, 20pp, (Gain 2 Officer, 2 Enlisted, 2 Techs, PLUS Convert 2 Officer, 2 Enlisted, 2 Techs from normal service)
Let me game it out. Right now we need two more Explorer Excelsiors to meet our goal of five concurrent five year missions. We're building one Excelsior, which will need to be crewed in 2305. Assuming we get right to work on the next Explorer, we'll need to crew it in 2309. Each Excelsior requires O-6, E-5, T-5.
Explorer Personnel Pool:
2302 (current) Explorer Corps: 5 Officer, 7 Enlisted, 5 Techs
2303: 6-O, 7-E, 5-T
2304: 7-O, 8-E, 6-T
2305: First goes to 8-O, 9-E, 7-T, then we deduce Excelsior, and it drops to 2-O, 4-E, 2-T
2306: 3-O, 5-E, 3-T
2307: 4-O, 6-E, 4-T
2308: 5-O, 7-E, 5-T... and we don't need to do a recruitment if the Academy graduation happens end of 2308/first thing 2309.
2309: First goes to 6-O, 8-E, 6-T, then we deduce Excelsior, and it drops to 0-O, 3-E, 1-T
Of course, that's assuming that we don't have personnel losses in the intervening years from some ship disaster requiring replacement from the pool. If that were to happen for officers, we'd have to do a Recruitment Drive.
Does all of that figure correctly?