I don't see how our signings from Southampton in the past should affect the club's decision. Also, if Southampton had kept all their best players they've sold to clubs over the last few years they would have one the best teams in the league.
No they wouldn't, only Luke Shaw and Nathaniel Clyne look the real deal, in my opinion. Everyone else they have sold has struggled to make the step up, Lallana, Lovren and Schneiderlin were all vastly over-priced.
Including player's further back they've sold
Clyne, Lovren, Shaw, Schneiderlin, Oxlade-Chambelaine, Bale, Walcott
And if you pretend they could still sign the players they've signed more recently without the proceeds of the player they've sold, they could combine the players above with the likes of Wanyama, Mane, van Dijk, Forster, Bertrand.
That would be a very good set of players.