Don't forget to mention that they were also being sprayed at on shore.

No doubt that snipers were there at the landings, but it would be hard for them to even hit any specific target like a machine gunner, with dust from artillery and sorts, they most likely couldn't see, plus the fact that the ships were moving so a sniper could've snipe before they were even on shore is past, mean they can shoot on the landing craft, but with movement from waves it would be an inaccurate shot.

on d day u.s.a used mortars grenadiers and snipers. but its a great map

this is ww2 almost every soldier had a grenade

Americans still did use grenades so grenadiers should be acceptable...