Flybe would be an awfully big mouthful (in relative terms) to be digested by the combination of Loganair and bmi. Furthermore, Loganair has prospered by being a rather conservative airline - they are not known for taking great risks.
That said, I could see Loganair biting off a *chunk* of Flybe - perhaps taking on some aircraft, crew and the thinner routes from Scotland to airports in the rest of the UK which won't support double daily A320 service (most definitely not the ones to London)