Aircraft played a significant role in the conquest of Iwo.
First it was bombed, but with rather little effect.
It was the Navy attack aircraft, mostly F6F's I understand, that were most useful, using Napalm, bombs and rockets to bust many of the hundreds of bunkers and nests that wer scattered all over the island.
We did not have any aircraft over here...yet.
Anything else is quite original. My whole gear for instance is all 40's, Just have my own panthies and that's it. Got to lob around 12 hrs a day in full uniform, with helmet, leggings, ammo belt which is promtly stamped "1942", military boots from the same time, a rucksack with a shovel and the pride, an authentic Tommy gun, muhahahaha.
There are all those Higgins boats, LVT's and Shermans, as well as Howitsers up to 105 mm (noisy bastards). But no aircraft.
AFAIK Eastwood is trying to make this as authentic as possible, but a squadron of F6F's on the scene is perhaps asking a wee too much.
Anyway, the project rocks, - big time.