A passing notion for the brawling, hacking, smashing of melee combat: Let fighters keep on rolling if they hit but shift the die used of r the hit die down and come up with a different attack.
Example: Earl DeDuke has a total hit bonus of +5 he's facing A pair of peasants in with shabby protection making them AC 12 (yeah I'm going ascending it makes the math easy). Earl wins the initiative rolling a d20 to hit for a roll of 12 and a total of 17 bashing the first lowly peasant in the jaw with his shield, he swings his blade at the other rascal rollign a d16 for 15 points that;s a total of 20 another sure hit hacking the lout with his trusty sword, but not dropping him so he rolls a d12 getting a 8 , good enough to land a knee to the groin nd giving him the opportunity to crack the oaf in the head with the pommel of his sword with a d8 roll of 7! Earl DeDuke lays low the two foolish peasant!
Two weapon combat variant.... uh, you have two weapons right? It's one of those dice rolls.
So first strike 1d20, second d16, third 1d12, fourth 1d8, and 5th... well, I suppose you could roll a d4 but really yuo have to have a discrete attack. Miss on any of those rolls and you don't get to keep rolling.
Damage for kneeing, headbutts and such 1d6-3, apply STR modifiers to the modifier not the first roll so the damage roll for STR 18 (with a +3 damage mod) is 1-6, not 4-6. Have it be stun/subdual damage if your game goes that way.
Bashing with shields and pommels of swords should likely be d3.
Higher level fighters typically allowed additional attacks should likely be allowed to ignore a miss and re-roll the next die down just in case and even get to pick the same attack form if desired.