McD has been pretty decent at scoring points in the NHL. 7th in ES points last year (among D-men) and curretly 13th. He doesn't get PP time so he can't score points there.
Girardi isn't a better RH option at the point than Strålman, who possesses a better shot, more willingness to use it, and is better at moving laterally along the blue-line.
He was 7th in ES scoring, but he also logged top 5 minutes. His p/60 rating is more telling of his offensive capabilities. Very average, but best on team last yr. If he had a RH shot, then yeah, I'd say he should be on the PP. While having these tools, McDonagh is not a smart offensive hockey player. I don't think Stralman is that good either.
Girardi is useless as a pointman and should essentially be our last choice on the point among defensemen, only ahead of Eminger. He's a very effective defensive defenseman, but he's a terrible breakout player and not an effective QB by any stretch of the imagination. He's a below average passer and puckhandler, never shoots and only has a wrister that he can occasionally pray will be accurate enough and completely screened to result in a goal. Which almost never happens.
McD has the tools, but not the patience yet. It feels like he has hit a rut offensively this season and shouldn't be on the point either. He doesn't shoot enough and that's a problem, because his passing and offensive awareness doesn't make up for it. He sure has potential though.
My choices for PP pointmen:
Zuccarello: Easily our most creative player and a fantastic passer. His point shot is acceptable, nothing more.
Strålman: Sadly our only defenseman that can actually shoot the puck and hit the net. He's a smooth passer too. He's a poor man's QB, but unfortunately we're a very poor team in this regard.
Brassard: Also a great passer and creative with the puck. Has a good shot. Give him a chance.
Richards: He has a real good shot when he uses it and still isn't dead yet. When he's alive, he's still good. He should be our great PP QB on the team, but sadly, he isn't.