Well, it has been a l-o-n-g time since i wore the uniform, but back in the day I spent some time crewing an M113 APC. A lot has changed since, so much so that at the last Veterans Day parade I attended, except for 2 1/2 ton trucks, there wasn't a single weapon or item of equipment carried over from my army. Some items of gear that passed in review I didn't even know what they were supposed to do

In olden times, my only multi tool was a four implement Kamp King pocketknife. All I needed it for was normal everyday purposes; opening cans and bottles (no pull tops then), cutting stuff etc. A pliers-based multi tool might have been useful, but Tim Leatherman hadn't yet taken his fateful European trip. Frankly, I never felt the need for pliers or saw as part of my personal gear. All the tools needed to maintain an APC were carried on board, especially mine, the shop vehicle for an armored unit. We even had axes, saws, shovels and just about anything else that might be needed in the field.
My guess is that a present day amtrack crewman would be equipped by the marine corps with whatever tools would be required for weapons and equipment maintenance, so no need to burden him with additional stuff that might be redundant. These guys are often called upon to hump a lot of gear, and ounces count(ses

). For EDC, a lighter weight Leatherman, like a Juice, Skeletool, or even a Blast, would serve nicely. Also, an SAK can be awfully handy, and nothing delicate about them in field use, either.
But, as I remarked earlier, much has changed, like for instance special tools were not required to disassemble, adjust or unjam any of the weapons I was issued, at least not at the field level. Although I haven't followed these matters closely, I believe the M16 family does require gizmos. If so, Uncle probably supplies those. Otherwise, ignore the above commentary and get the lad an MUT.