Monarch have a fair number of based aircraft at MAN on multiple rotations per day, not something anyone over at T2 currently has, I don't see the logic.
T2 stands mainly empty for periods each day as well.
Unlike TOM and TCX who tend to stagger their departures through out the day, MON tend to dispatch their flights at roughly the same time - first wave between 7-8am-ish and and second wave at 2-3pm-ish ( a headache for Swissport manpower planning ! ) and during those times, T2 can be quite busy.