A lot of them will simply relish the opportunity to pit their training and skills against those of the enemy whilst fighting alongside their mates. It's the ultimate test, if you want to look at it that way.
The "ultimate" test ? Really ?……….surely the ultimate test depends on the "enemy" ? 😕
Presumably the ultimate test of pitting your training and skills against those of the enemy, would be to fight an enemy who had an airforce, tanks, heavy weapons, etc ….. just like you have. And to stay in the conflict zone not for maybe 6 months, but until the conflict was over – years if necessary.
I'm not sure that calling the US airforce in to demolish the side of a mountain because someone has taken a pot shot at you, necessarily represents the ultimate test of your training and skills – although obviously it is some sort of test.
Thankfully it's been quite a while since British forces have been expected undergo the ultimate test of their training and skills. And hopefully it'll stay like that.