I think it's a mistake not to use part timers when you have blockheads like Shahdat. Otherwise,not really, because there should be 5 guys in the team who train more than others on their bowling in practice and thus are entrusted to have the most skills and preparation going into the match.
I thought Mushy could have given Mominul a go. But not Ash. Ash is not a successful part timer, easy to smash for sixes.