More like royal commandos because they are royal marines
And USMC has al types of vehicles and aircrafts.. Dutch marines just have soms small armored vehicles. But it isn't a whole army. They're a specialised infantry group.
Yes, the RNLMC is much like the RM. In fact we work together A LOT
There's a NL/UK landing force for european missions (peacekeeping/enforcing). The Dutch SBS is actually under british SBS command during war (both the british and Dutch SBS are part of the Marine Corps). We also have a Mountain Leader specialist course, which is actually the same as the british one.
Our Officers training includes going through the RM commando course in England and we have a British Colour Sergeant attached to the entire officers training course to make sure that our officers are on the same level as the british ones and that we can work together with the british.
The USMC, with all due respect, is not much more than the US Army with wet feet. It's not really a specialized infantry force, but has it's own armor and even an air force. Not bashing on our American friends, though. I really like the US Marines, but it's just that it can't really be compared to the RNLMC (I'm not talking about the MFR and FAST units)
The RM and RNLMC are specialized light infantry. If you want to compare them to an American unit I thing the US Army Rangers is the best to compare it with (when looking at the elite status of the unit, of course the Rangers have a completely different job).