I'll agree with you that the old system was inefficient, but what I don't see is why displace crew.
To be honest, where the crew are based is irrelevant, as long as a line of work rotates through their base. You could easily start and finish a line of work from INV, or ABZ or NCL as easily as MAN.
Look at how they ran the Brussels contract. We all started the lines of work in BHX or EDI.
Yes, this will involve a touring roster with night stops, but that seems the way Flybe are going now anyway. It also negates the hassle and expense of moving to the other arse of the country. More importantly, it keeps the crew happy.