The trick to speedy combat is the type of weapon on the enemy you fight. Generaly beings that can feel pain and have blood and can bleed are quite easily dispatched. The other rule is, if it can't bleed, smash it to bits. Colosuses for example need to be cut apart or smashed apart, a axe or blunt instrument works.
These methods are active close combat, no sneaking, no ranged attacks, just brutal mortal combat.
1.Method on anthropod with light armour (cloth,leather) and unarmored fleshy foes (most animals):
Weapon to use: sword or axe , high shear yield (steel, iron, bronze, adamantium).
Disable by cutting off a lower extremity and cut off the weapon arm, stab into the upper or lower body, move onto next target. (3 turns minimum)
If time is of the essence, cut off weapon arm and move to next target, enemy will usualy run away bleeding and collapse. (1 turn minimum)
2. Method on heavily armoured anthropod (chain, plate, chittin).
Weapon to use: warhammer, mace, maul with high density and plastic deformity capabilites (silver, steel)
Disable by hitting outer extremities and causing plastic deformity on the armour and bones. Once the bones go, enemy colapses from pain sooner or later. (3-5 turns minimum).
If time is of the essence, hit weapon arm or hand or a easily hitable part, once your victim is screaming in pain, go for vital parts, like head or chest, turning organs into mush (2 hits, 2 turns), move to next enemy.
3. undead and zombies
Weapons to use: blunt weapons as mentioned in section 2 and cutting weapons to remove body parts.
Don't davdle, remove a lower extremity, so it is slower, then start smashing the head in till it's mush. If thing keeps moving, go for the necromancer responsible.
piercing is innefective, because the organs are not responding to trauma, since they are dead, removal and blunt force only work.
4. Group fight against pack animals (wolves, coyotes, boogeymen.)
Move as much as possible away from the swarm and attack only one on one, disable as mentioned in section one then move away when the rest of the swarm gets closer, repeat ad adendum until the group is disabled and routed, running away and bleeding.
Night creature fighting is mostly running away and doing quick slashes and hits, then continuing to run. If boogeymen swarm you... it's over, they will beat you to death. It is very effective to use charging as a default attack, though use it sparringly and change accordingly on the location.
5. fighting against ranged fighters (crossbowmen, bowmen).
Take cover behind trees, if that's not possible, look for lower elevations or if you are really in the poop, throw yourself on the ground. High shield or dodge skill is very important and archers and crossbowmen hit prone targets harder.
going into sneaking if it's possible will make it easier to run up to the archer, otherwise, use trees as cover and run from tree to tree.
When you are in close combat range, disable archer by cutting off weapon arm where the bow/crossbow is held, for added satisfaction, cut off both arms just for him being a ranged fighter. Move on to next target, archer will bleed out. (1+1 bonus turn).
Another method is to grab the bow with wrestling and wrestle it away from the archer, then stab enemy into upper body, disabling him with a low cut of the legs and letting him bleed out, move on to next target. (3 turns).
These combat techniques are mostly meant for quick effective fighting and disabling against larger groups of enemies, goal is to disable and move on. If the enemy doesn't have a weapon and is bleeding out, you have won that fight.