Well, yes, it's useful that way. It scales a bit closer to 1/35 than 1/32 in any event. It also has that moulded-in rope "gunn'l" more typical of Army LCVPs, too.
The gun tubs would be tarped over, like as not, too. For river crossing, you'd likely only see them with two hands, a cox'n to 'drive' and a boathook/rampman, who'd likely be riding the lookout step on the starboard side of the ramp (as opposed to "by the book" USN practice, where there'd be a "Motormac" as well).
As to which vehicles, that's a limit of the ramp, the driver, and the vehicle not being more than 8000# loaded, IIRC.
Now, I want to remember that there were a lot more "Mike" (LCM-3) boats used crossing the Rhine than any other type. (Cool dio possibilities using the big "dragon wagon" tank transporter & an LCM-3--other than needing a whopping big case for it <g>.)