yepp, this is not simple if they want to be realistic, they could give a negative effect while wearing big weapons or armor, but this would only be a pain on the neck to unequip everything if we want to sneak.
Otherwise if they would want to be more realistic, all characters should walk around with a large backpack or pulling a cart if they carry much things. And they should be slower too, which is painful again, since they are already slower than usual.
