I didn't say where to go/where not to go. Go where you want to go, and do what you wanna wanna do. (Sorry for the shameless Mamas and Papas plug.)
"The idea" is that there is no silver bullet that will guarantee you anything in the military, other than the chance to serve. Military assignments, as I said before, are a unique blend of meritocracy (did you earn it?), timing (do they need you in a certain place at a certain time), who you know/who knows you (just like everything else), and - sometimes - just a lot of dumb luck.
The only thing you can fully control is your performance. It must be noted, though, that if you give 100% of yourself, 100% of the time, things have a way of working out for the best (even if it doesn't seem like it at the time).