Looks like they've left Manning and Mantz out of the first attempt to fly to Howland
Mantz only flew as far as Hawaii -- it was Earhart, Manning, and Noonan aboard NR16020 for the attempted flight to Howland. Either way, Amelia and Fred seem to be the only ones who made the cut for the movie -- Paul and Harry are nowhere to be seen (in the plane or on the ground).
Filmic storytelling is all about streamlining and effeciency. The many advisors who actually consulted on AE's planning would be only so much clutter in a two hour movie. I suspect that, given the emphasis placed on her relationaship with Vidal (plus the "map scene" on the web), most all of their contributions have been consolidated in Gene.
--R