From what i can see wolfgang is all perks with no real downsides so why not give him a downside that sort of applies to his character in the game.
currently the only downside wolfgang has is a higher sanity drain from monsters and darkness which in reality isnt even a downside as he can just kill the sanity monsters in 3 or 4 hits so why not make sanity affect him differently as how willow is affected with her freeze effect.
lets make wolfgang actually scared of monsters. How this would work is when his sanity gets lowers he begins to miss when fighting (probably like how weapon slips work when you are wet). this makes his downside of higher sanity loss even more prevalent has wolfgang would have to keep sane to really fight anything and cant just be a all powerful being that doesn't even need to care about his sanity.
I only suggested this cause really sanity is not a factor to a lot of median to high level players and this reason is why Wolfgang is pretty much the best solo character. This should make him a little more balanced
got 2 suggestions of how this would work
a max of 10 percent chance of weapon slipping at 0 sanity and it ranges from 100 to 0
30percent at 0 sanity and 0 percent at 100 sanity scaling as he goes insane