I'd just like to point out that Ninja were very often trained to use the weapons of their enemies, and also in disarming techniques meant to acquire them. Yes, swords were illegal for them, but then again, Ninjas are already illegal anyway, so why would you assume they didn't train with them just because "not available to their caste"? They fall outside of the system.
At least, that's what 2 years of studying Japanology (yes, it's a thing) at college taught me.
I also agree that a ninja would do whatever it takes to get the job done. Whether a particular Ninja knows how to snipe is a case-by-case deal, but all of them would use a sniper if they knew how and the situation called for it. And since they're trained from a much younger age than our current soldiers, direct comparisons to mental states, training time, etc, may not apply.
Maybe some Ninjas would even use Skillwires to complement their art? (like, they'd know stealth, infiltration, disguises, a few weapons, and then if they needed a very specific skill for a 1-off thing... skillwire)