I slightly disagree. From what I understand about the diamond, Lampard would be a terrible fit as a LCM or RCM. Needs to run too much.
The problem with NYCFC is that if you are going to put Pirlo in front of the CBs as a CDM, you need to have two box to box hard runners to cover the ground that Pirlo will not do. (See: Vidal and Marchisio). That leads you to play the 4-4-2 diamond most likely, or a 4-3-3.
The central issue is where do you play Frank Lampard? He's not a Vidal or Marchisio and it is suicide to expect his 38-year old legs to run like a bulldog. But he needs to be on the field. So do you play him at the tip of the diamond? Frank is not a CAM either. You can't play 4-3-3 either because Frank is not a LW/RW/ST either.
If you are playing the 4-4-2 diamond with the players you have today, you put Pirlo at the back, play Mix and Tommy Mac (the two midfielders closest to the Vidal/Marchisio role) around him, put someone like Poku in front of them, and then play Villa and Mullins up top. If you had to put Lampard on the field, the only option is at the tip of the diamond but he's not going to provide that linking play and would probably be running into Tmac and Mix trying to play their role.
Now, if you get rid of Pirlo and go something more like 4-2-3-1, there Lamps plays well as one of the 2 (would partner great with Mix as box to box midfielders) and you could play a front 3 of maybe Tmac, Poku, Shelton and Villa up top. Or 4-2-2-2 with Lamps, Mix, Tmac, Shelton/Poku as your 4 midfielders and Villa/Mullins up top. Or even put in a Ballouchy as another mid to control possession late.
Oh wait. Scratch all of this. Forgot this is Kreis, Grabavoy needs to fit in here somewhere. I give up.