Does Coyle have no input? This kind of cock up was rare when we had BSA. He knew how to buy and sell, not that he was infallible.
You can't say Allardyce knew when to sell because he was rarely in a position to buy players with any sort of resale value. In fact the one comparable scenario I can recall is with Ben Haim, which Allardyce screwed up.
Of course we did make a decent profit or at least get our money back on his younger signings (Anelka, Diouf, Meite, Faye) but he wasn't the one who made the call to sell.