Is there a way to configure Skyrim to be like Oscuro's Oblivion Overhaul, where it makes monster difficulty more realistic?
That Oblivion mod did so mainly by removing monster level scaling with player level. Monsters were given a static difficulty based on their type and some other factors. For example, all wolves were easier than all trolls. I enjoyed the challenge of being aware of the type of enemies I was facing and needing to test whether they were too strong. In the built-in system, it's generally possible to kill almost anything starting at early levels, and there is no sense of excitement at being able to go somewhere that had previously been restricted.