But in the situations I have seen (beer bottles smashed on guys heads, and bats being used), strength played an important role in landing a solid blow.
PP, in case this was misunderstood,
I personally never said strength was immaterial. Especially in hand to hand combat. I said it was not definitive when it comes to killing.
Killing efficiency is.
Strength may very well be definitive in winning a brawl or a fight, which is a different kind of fight than a killing combat situation.
Strength also doesn't make you better at hitting if the other person is well trained in combat unless their movement is restricted in some way, or they are tied to a place, or voluntarily engage in a stand up fight.
From what I'm understanding of your examples you are saying strength tells after a blow (after someone has been successfully struck, someone can also successfully use speed and training to avoid blows), and that can very well be true. But it doesn't make you better at hitting, and especially not at killing, unless you know how to hit, which comes into play from skill, training, and practice.
Let me put it this way. The very first time you sparred, and that's a static fight compared to a lethal combat (you are purposely engaged with each other to fight in a face-off), were you very good at hitting your partner? Probably not. In time you practiced and learned proper technique. Then you became good at hitting the other guy. You learned how to actually fight.
Now once you learned to fight well, then you could apply your strength properly. Your strength had effect whereas before (even if you had been at the same relative level of strength) you would have been less than ideally effective.
Same thing with killing, and real combat.
First you have to know what you're doing, and then later you can better exploit your other talents, speed, muscle control, strength, power, movement, tactical knowledge, accuracy, even intuition, and so forth.
A novice may be fast, or strong, or anything else, but generally speaking he's probably not very good, or the strongest boxers, or fastest, would always be the most effective boxers. Or the strongest men the best killers. But they are usually not.
First a guy gets good at what he is doing and then he becomes dangerous. But he is not dangerous just because he is strong,
he is potentially more dangerous if he knows what he is doing and is also strong.
That is to say that every advantage helps once you know what you are doing, but almost none do if you don't know what you are doing.
I hope that better explains what I was saying.