I'm sorry to say some of you have it wrong. Combat is never and should never be balanced beyond certain limits. An archer should tear through most troops at range. A mounted warrior in a charge or fast moving horse archer the same. Even a heavily armed warrior on foot should defeat a lighter armed opponent. Its not about balance for every fight its about giving the option to counter your opponent. If You come for one type of fight and I am armed with your weakness as a counter then you should probably lose. Combat impairments are about new options rather than cookie cutter battles where you time this and do that. Combat should be fluid even if coordinated.
You all want fun unless it gives someone a chance to upset you and your well practiced timing of game mechanics. NO! A new player should have a chance to evade and fight. Im not saying it should be balanced so they win but if that person has an advantage in terrain, movement, vision... yes that should matter. No battle should be a sure thing no matter how skilled you are.
The three things that affect combat the most are equipment quality, morale, and skill. Morale should never be programmed in Haven as it will never reflect a players desire. Beyond this as i mentioned terrain, vision, and such should be secondary concerns.
Now the argument that these would not be fun... why? Skyrim, Fallout 4, Minecraft... all have vision limitations that if you can not see it you can not attack it. These are mainstream games that sell huge amounts of product. They are fun and integrate this seemlessly into the system. So why are these unfun aspects?