The thing about Harry Kim though, wasn't he already the lead Ops Officer before banjoman made everything all explodey? It's been awhile since I watched the ep, but I seem to remember it that way, instead of how everyone else tries to rules-lawyer the issue to fit their personal belief that the position requires a higher ranking officer (like Lt Cmdr Data).
The thing to remember with the OPS position on TNG, is that during the first season we often see the junior officers (at LT jg) Worf and La Forge sit at the position quite often, and throughout the series there's instances of nameless yellowshirt ensigns sitting there when Data is off ship.
I think it's acceptable to think that Harry Kim scored well enough at the Academy, and that Voyager was a small enough ship, that he was meant to be the Ops officer from the very beginning, with maybe another slightly less smart Ensign as backup, and then enlisted personnel filling out the department (with various other engineering staff taking turns for cross training, etc).
As for the main issue, you have to accept that each captain will have his own preferences for whom they consider their "top" senior staff, ie, their command crew. Some may be close to their Chief Medical Officer, others their Chief Engineer. As long as Trek has to play by the rules of screenplay drama, we're not going to get a definite answer anytime soon on official Starfleet policy on the practice.
And as for "junior" officers like Chekov and Sulu sitting on briefings and going on away missions all the time, I've always seen folks like that as command-track "interns". The commanding officer has noticed an ability in them that he wants to nurture and encourage, and so they become default senior staff.
The thing to remember with the OPS position on TNG, is that during the first season we often see the junior officers (at LT jg) Worf and La Forge sit at the position quite often, and throughout the series there's instances of nameless yellowshirt ensigns sitting there when Data is off ship.
I think it's acceptable to think that Harry Kim scored well enough at the Academy, and that Voyager was a small enough ship, that he was meant to be the Ops officer from the very beginning, with maybe another slightly less smart Ensign as backup, and then enlisted personnel filling out the department (with various other engineering staff taking turns for cross training, etc).
As for the main issue, you have to accept that each captain will have his own preferences for whom they consider their "top" senior staff, ie, their command crew. Some may be close to their Chief Medical Officer, others their Chief Engineer. As long as Trek has to play by the rules of screenplay drama, we're not going to get a definite answer anytime soon on official Starfleet policy on the practice.
And as for "junior" officers like Chekov and Sulu sitting on briefings and going on away missions all the time, I've always seen folks like that as command-track "interns". The commanding officer has noticed an ability in them that he wants to nurture and encourage, and so they become default senior staff.