Does the boat HAVE to be dragged 3-4mi? Does the insert HAVE to be by CRRC? Maybe we've always done it this way because muscling through it was easier than thinking about it. Could you make a lighter boat?
The Sailors that worked the hardest and hustled the most when I was a Mini were the 4' 11" women. Despite their small size they routinely outperformed the men.
I'm not saying that women aren't hard workers or lack hustle. I'm saying that when you are 4'11" the rigors of combat arms are physically going to break you/make everyone around you carry extra weight.
The boat example isn't even a far fetched one. That is literally 1/3 of the grunts in an infantry Bn.
So, imagine we say screw it, the mission of sneaking in in the middle of the night on low radar cross section boats and destroying enemy whatever (usually ADA to start creating that foothold) and sneaking out before dawn is a stupid one. Let's get rid of it.
What do we replace those Marines with? Well, another 1/3 of an infantry Bn is helo company - so maybe we just double down on that or something (poof more helos [ok Ospreys: vertical lift, you happy?]). Usually we have to land to the offset, so you are looking at a 1km foot movement right off the bat coming off the bird. Figure 80-100 lbs pack, +Flak, water, ammunition, a few extra mortar or rocket rounds, maybe a can of 7.62, or a PRC-117, etc...you get the picture. Or maybe we just get rid of the offset and make every landing to the X, less than 300m from the objective. Progress.
So I guess we could put everyone in amtraks, so they don't have to carry a pack or anything - and then the 4'11" Marine can get a taller Marine to throw her pack up on the rails on the side. Progress I guess? (Except we got rid of boat company, so without anyone to sneak in and set the conditions, now the traks have to go in Tarawa style...which will facilitate drafting a lot more female Marines in short order).
I default to: What are we gaining and what are we losing? I don't see a lot of gaining to be honest.