This has been debated before when it was relevant to us , however in the interest of veracity Valencia were in chaos both in the dressing room and the boardroom long before Koeman arrived. In fact he was more the victim than the perpetrator. The true story is out there if you care to seek it out.
Concerning Barkley , if Koeman was so awful to Barkley it is strange that shortly after joining Chelsea and after Koemans dismissal Ross gave an interview praising Koeman for improving him as a player and expressing sadness at his dismissal.
The only reason Barkley left us is because he wanted to and had decided to do so before Koeman had even arrived.
All largely irrelevant to us now , but I prefer to read facts rather than self perpetuating myths.