Every soldier is an infantryman first and everything else second. For the record, most of my career, I was assigned to Infantry units.
No, it's not just that they work for "less", but that they work a lot harder.
Fun story I like to tell. When I worked for the company that eventually cured me of Republican Stupidity (long story I won't get into here), they used to hire contractors to do the scrub work (Cleaning up, packing kits, etc.)
The contractors were hired through a temp agency. At first, we only had two of them but as the business grew, it expanded to six.
Well, after I left, the company was bought out by a bigger company, and their first edict was that every contractor had to be an American.
So the hard-working Mexicans disappeared, and white meth-heads replaced them. I wasn't there personally, but the ladies who worked there told me they were TRULY scary-looking dudes. And of course, they wouldn't show up on Monday after they got their paychecks because they'd be out getting high.
You keep telling yourself that.