I think T3 are quite safe on MME-ABZ. Flybe tried a Q400 on NCL-ABZ & that didn't work - I think about 20-30 on each flight, not enough yield for a Q400.
Unless Loganair finds more Saab340s from somewhere, I think T3 will have sole preserve on ABZ.
Of course, prefectly possible a Q400 would work on other MME routes.