You have to restrain all arm slots and mouth in order to stop the enemy casting spells in current version of the game, not just the wrists. The same rule is applied to the player. So if you are in 1v1 combat the most efficient way to win combat is to go for all arm restraints and mouth. Just bare in mind that stats play a role in turn order and restraint resistance/strength so go for equally leveled NPCs. Though you will probably raise commotion to the max value and all free enemies will rush to you. The commotion mechanic needs updates. There will be a tutorial in the future when the main gameplay loop is established.
I am currently working on an overhaul of the NPC subsystems. With your feedback in mind, I will do something about the difficulty when I finish the stuff that is in progress right now.
I also wanted to make the combat faster so I would appreciate if you could tell me if the pace feels slow.