And your point is....???
The Marine Corps is an Air-Ground Team of LIGHT infantry whose specialty is forced entry to a foreign shore, thus enabling the army to land safely and without getting their feet wet (their specialty is the unopposed landing, of course) in order to “win” the war. “First to Fight” means just that. We enable the army to do ITS job. We take nothing from them in that regard. INCLUDING, I might add, the guff that is typical of the army with regard to our job and our accomplishments.
I trust that will satisfactorily answer your query. Always pleased to educate and enlighten my doggie brethren (and sistren)...
North Africa, Sicily, Salerno, Anzio, South France Leyte, Luzon and Normandy were all US Army amphibious assaults. Somehow, the army managed to assault all those beachheads without a single marine unit.