To be fair, that doesn't sound like a problem with game balancing.
If it was a problem with game balance, then it would have affected everyone & I had absolutely no problems.
It sounds more like a problem with the player not doing what's necessary.
There is no way it should take "300 turns" to get 1 fiefdom under control!
Did you build the Shadow Institute? From there you can throw a Festival to raise Morale, or you can Bribe the Clergy to raise Obedience (both at a cost of some Gold).
Did you build a Garrison? Placing just 10 troops in there will easily deal with Raids.
20 troops will stop Obedience from dropping & putting 30 in there will cause Obedience to rise.
Having higher Morale makes the likelihood of a fief producing extra Gold\Troops increase, so getting back lost soldiers should not be a problem and should not take very long.
The
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will help you to understand the mechanics better. I'd advise using it.