Of course you can go with an AHL coach. Sullivan's Cup-winning predecessor (Bylsma) was also an AHL coach. Helps to have the Penguins players too doesn't it? But the Flyers have also had great success with their NHL retreads - Nielsen, Hitch, Laviolette - for as long as they lasted.
Anyway, don't think you can expect this front office - even Fletcher - to hire an AHL or junior guy this time. They can justify keeping who they have - also a good AHL coach (before he failed on Long Island) - or they can make the splash. (Also I wonder if Keefe will just get promoted to Toronto assistant so they can keep him).
To say they have been truly worse under Gordon seems like a stretch. If anything it shows the problems are much deeper than coach or system.