[NPC] Smart NPC'S

I think it would be cool if NPC'S will use their brain when they get hit by an enemy, for example:
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Enemy hits arms dealer: he starts shooting at it with a flintlock pistol
Enemy hits demolitionist: he starts throwing grenades at it (at a slow speed)
Enemy hits wizard: he starts casting waterbolts at it
_
I'm not sure what the rest of the NPCS would do. Maybe the mechanic would swing her wrench at the enemy?

This would be awesome. I always hated it how the arms dealer would run away when hit. even though he has a infinite amount of minisharks and bullets.
Other ideas

Guide:Iron broadsword
Merchant:Iron short sword
Goblin tinkerer: Uses spiky balls.
Dryad: Throws dirt (Lol)
Nurse:would run away And heal Injured NPCS
Clothier:Turns into skeletron (Just kidding)

Mechanic runs to Goblin Tinkerer for protection.
Guide opens door for other enemies.
Dryad instantly transforms into a sapling.

Clothier: throws red hats

Mechanic:Flips a switch and a boulder falls on a mob
Goblin tinkerer:Flys to safety on rocket boots
Guideies

Guide:Runs at you,and start an annoying dialogue,saying that monsters are attacking your base,and does not let you do anything else until you not close the conversation,or dies.

They could at least learn to stay inside when the world is full of goblins.

This would be awesome,if it would be for pc anyways..
-Dryad:Uses vile thorn and ivy whip
Other ones are just too awesome