Kirk's Enterprise has been taken over by his first officer
In which case Security would have sided with him, and did.
a bunch of 1990s supermen
Who probably outnumbered the Security force even if one doesn't count them having the drop on the
Enterprise folks, superior prowess in hand-to-hand, plus inside help from McGivers.
In an episode where the redshirts put up a valiant fight at every step.
Not exactly. Not even their pimp ever "took over".
Now
their pimp did take over. But that's par for the course for superhuman creatures.
At most, they effected an escape...
an angsty teenager, the Kelvans, a computer, a glowy thing, Scalosians and one of Kirk's exgirlfriends.
You forgot at least the invincible wrecked space probe, and one of Kirk's ex-boyfriends. Both of whom were immune to physical resistance.
Yeah, those children are grown-ups reverted to childhood, one of which being the captain, but still that doesn't speak volumes about security's skill.
But Security was ordered to stand down by Riker. We don't know if boarding was successfully repelled in other parts of the ship before Riker locked the computer and surrendered.
I do like the idea that Security would be a scaleable force, with just a small core group dedicating 100% of their time to security duties and the rest being e.g. engineers. That would jibe with the massive reassigning we hear of in "Chain of Command", as well as with all those TOS cases where Security is mobilized but explicitly comprises less than a dozen people ("Devil in the Dark" is a good example). The "security vs. deputy" issue could also affect the prowess of the force: we'd see one of 'em highly trained combat specialists in, say, "Doomsday Machine" where Decker and his escort beat the crap out of each other before the former gains the upper hand, and one of 'em deputies in, say, "Mudd's Women" where he stands guard without making an effort to eavesdrop on the activities of the perps in his custody.
Timo Saloniemi