Yes, he's PROBABLY all right when it comes down to stamina I agree. But there's a chance he'll still be left wanting late when facing a strong pressure fighter like Mormeck. It's hard to forget the image of a static, robotic Haye hardly being able to move against Carl Thompson. He made a spent Frank Bruno look like Pernell Whitaker at that moment.
He wasn't used to fighters being able to take those punches, he just kept battering away and punched himself out. I wouldn't generally call Haye static and robotic and he's never done the Bruno thing where when someone hits the magic button, he drops his hands and stands there like a Mortal Kombat character awaiting a fatality.