My recollection of MacK's one timer is that he has always been very picky about the placement. He's not a Stammer or Ovi that can rip a one timer from basically a 2' area... he needs his in a specific tiny area. I remember how frustrated people were with Barrie not feeding him perfectly for it and blaming Barrie.
I really wish that if MacK is to be used as the trigger guy that he'd open up his range and work on one timing imperfect passes more. At his talent level, it can certainly be learned. Franky, more reliance on Mikko as the trigger guy would probably be helpful, but you'd ideally want a lefty running the point then.