I can’t think SOU management will let that concentration happen again, now having a pretty balanced airline customer group including KLM, BA CityFlyer, Aer Lingus by Emerald, Loganair, Aurigny and Blue Islands. They just need a bit more leisure capacity, Air France in some shape and then Aer Lingus Regional on DUB as well as BHD.
Eastern do seem to have sealed their own fate at SOU with things like suspending Manchester for two months (during rail strikes and Heathrow disruption too) suggesting that they’re less than serious.
Chucking Flybe into the middle of this mix and them competing with almost everyone else - KLM, Loganair, Emerald, Blue Islands and so - will just cause no end of mess and potentially some long term damage. We‘be all seen routes go from one carrier to two and then to none.