Hopefully, the kit figures have been reworked. The originals--from thirty years' ago--were under-scale, about 1/37-1/38 (the kit dimensions are closer to Army-contract Higgins at 1/34--mostly).
If gunners were in place, they'd be bundled in kapok life jackets, and would near fill the tubs (even if you enlarge the tubs to correct dimension. The cox'sn (coxwain, boat driver) on D-Day might or might not have a helmet. Most had sou'wester rain hats, along with oilskin jackets. Book regs required them to have kapok life jackets, but these were often given over the side to GIs in the water.
The forward lookout (not in the kit, but needful every trip) would be in full foul-weather gear, ans an overcoat. Underway, the lookout manned a step on the starboard side just behind the ramp. He was the eyes for the cox'sn in the blind spot. Almost all film & photos show them with a helmet, usually as deep on their heads as would go; dripping wet. The lookout had to stick his head out from behind the ramp as the boat comes ashore. He has to look down, too, for obstacles, and to know when they had the boat over the last sand bar . His was the signal to trip the ramp hook, and carry it on the ramp winch brake.
Which was manned by the "Motor Mac"--Motor Machinist Mate--who kept that one engine running. Which was a task, since the sand filters had to be cleaned, the fuel & temps monitored, and to man the ramp winch drum.
For army figures, the AirFix Multi-Pose are quite excellent, a kit worthy unto itself.
Only flaw with that, to my opinion, is that they are clearly near 6 foot tall 1/32 figures. They'd look to be near 7 foot tall using the Lindberg figures.
Hope that helps