Because at tiered parks you have to worry about the tiering restrictions. In addition to what
@marciemi said about strategy at MK you could also schedule whatever 3 rides you want on each ticket (so have 6 headliners booked or 2 rides on one you love but wouldn't ride standby). After using the 3 on the ticket you used to enter the park you begin to transfer from the donor ticket and as you transfer add a new rolling FP to the donor ticket. Since there aren't tiering rules you can add ANY attraction to that donor ticket as long as you don't try to hold 2 FP for the same attraction with that ticket (so you can ride space mountain or big thunder multiple times if it is avail). So if you schedule your actual ticket FP for 9-10, 10-11, and 11-12 you could tour for almost an hour when the crowds are low then hit 2 FP in a row (just before and just after 10), hit a ride with a short standby line then finish your 3rd FP by just after 11. Schedule the donor FP for 10:30-11:30, 11:30-12:30, and 12:30-1:30. Once you finish your 3rd FP just after 11 change party the 10:30-11:30 and reschedule the 3rd donor FP. That early in the day there should be good availability. Rinse and repeat. If you want to get even more involved you can try to start moving up the donor FP times when you schedule the new 3rd FP. So once you moved the 10:30-11:30 FP to the primary ticket (which you can do in FP line waiting for the 11-12 FP) you can try to move the 11:30-12:30 FP up to an earlier time (11:15/11:20). If you can move that one up then you can try to move the rest as well. If you can't then when you transfer the 11:30-12:30 FP to the primary person you can try to move up the 12:30-1:30 and the subsequent FP when you reschedule the 3rd FP on the donor account. Sometimes it is easy to move them up sometimes there is no earlier availability for that attraction. I do it while in the FP line if I bother with it.
ETA lol maybe I shouldn't give away all my secrets

Let's just say my son is a HUGE 7DMT fan and we have yet to wait standby for that ride-only ever saw the standby que when we had a CRT PPO ADR.