I don't think the 100% defense armor system is bad, but having 100% NO defense if your armor breaks; That's the horrid part of the system.
We can have both? Armor system in place and RNG defensive combat abilities from last game (ie Bodybuilding, block, willpower)
Perhaps the chances of CC after having their armor destroyed could be based on the type of armor they're wearing? Leather armor would have less of a chance to resist CC, while the heavier stuff would have the most. This would help balance the movement penalty for heavy armor more.
Obviously, this needs more thought. It'd require Larian to take a look at magic armor and separating that into categories of light and heavy, but it's an idea.