I think, if you listen closely, you will find that the definition of skill can be found in an unlikely source. I am speaking of course, of that famous Kenny Roger's Song: The Gambler.
As the well known Chorus says:
"You gotta know when to hold'em... know when to fold'em... know when to walk away... know when to run." Let's explore this further.
You gotta know when to hold'em... - Hold what? You're fire, naturally.
know when to fold'em... - the enemie's flanks, that is.
know when to walk away... - from that Tank/APC/Helo/Jet/Sniper/HAT/FAV/Grenadier kit which you have no business using.
know when to run. - when Big Red is in the area.
Sounds like skill to me.