This mod (specifically, the reduced health and reduced stamina mod) fixes the issue of combat being too easy by mid to late-game, especially when used in conjunction with this mod, which also increases the number of enemies that spawn in random encounters.
Before using these mods, I was killing anything in my path in one or two hits, and nothing was remotely challenging or interesting. Now, I’m in genuine danger whenever a large group of Cumans or well-armed bandits attacks me. I have to be extremely careful about not getting surrounded, since enemies have a habit of grappling me and throwing me into their groups (which often leads to me getting severely injured, even with plate armor to soak up most of the damage) – and in terms of AI, enemies are more aggressive about attacking when grouped together, as well.
I feel like I have to use my skill and wits to survive random encounters now. The mod isn’t perfect, since it buffs the health pools of all NPCs and creatures, but it’s a huge, HUGE improvement from the base game.
Wholeheartedly recommend, at least until a more elegant fix to combat comes along in the form of a weapon damage / armor rating overhaul.