SEN-MAN could prove very successful if planned right.
It would allow SEN pax to connect to their BE flights ex MAN (INV/ABZ/GLA/BHD/IOM/EDI) amongst others.
Furthermore Flybe interline with MT at MAN allowing SEN pax to fly to SFO/BOS/JFK/LAX/MCO/MIA/LAS without seeing their bags.
Flybe also codeshare with EK/EY/SQ & CX from MAN so you never know...