^ After a certain point, skill won't help you defeat a stronger opponent. That's only in the movies. That only works when they are close in strength. I'll never buy Kira taking out that Klingon, unless Bajor women are a lot stronger than human women, which might as well be the case.
What does Kira need strength for? Or even skill? She's fighting with a gun against people with swords!
That she takes down
one guy towards the tail end of the fight while using a sharp elbow is hardly indicative of superior strength or superior fighting skills - only of the fact that she's had it easy until then, while the Klingons have been moving and sweating and swinging swords and getting beaten. And the stab wound she received an eyeblink before need not have "kicked in" yet; we do see this happen just a few seconds later, taking her down, but initial shock could keep her from feeling the pain or the weakness.
Imagine if a man was bleeding out. His only hope would not be a transfusion from a horseshoe crab or common octopus. Likewise, red iron blood (or pink iron blood--hemerythrin?--if you wish) is not likely to prolong the life of a man whose biology runs on a copper-based respiratory pigment.
Let's remember it wasn't a blood transfusion that would have saved the Romulan. It was a blood component transfusion - "compatible ribosomes". No need to involve the red or green blood cells there in any way (those could probably be replicated in bulk anyway, as Picard immediately suggests replication as the remedy to the Romulan's shortage). And if anything is compatible between Trek humanoid species who are known to be capable of interbreeding, it's ribosomes...
Because I'd be able to take down a woman that looks like Kira with a finger of my left hand. And I'm above average strength, but not even big.
Not in the scene as depicted. She'd have a gun.
Hell, even having a knife would save her from you, because the use of a knife doesn't require any strength in the usual case. Your only hope would be to punch or kick her before she managed to employ weapons against you - another thing where strength plays no role, because if your kick connected with her jaw, she could be a 500-pound amazon and still die immediately, or be paralyzed for life.
Now, if Kira had elbowed that Klingon in the head area, there'd be no discussion here. You don't need superior strength with hits like that, you only need threshold strength, which most humans would have. A hit in an armored, padded stomach... Now that's where credibility is stretched.
Gunfights, knifefights, fistfights... They are not contests of strength. They only involve threshold strength, after which any extra strength is useless. With a gun, you only need the muscles to pull the trigger. With a knife, a little bit more. With a fist, a great deal more, but it's still just threshold strength. And stamina, unless your first few punches already do the trick. But stamina is something dependent on skill - on letting the other guy get tired. And Kira did a lot of that in the fight.
Timo Saloniemi