If you want a truly fair type of separation, consider a “someone takes all” scenario.
As an example, you and a business partner want to split from a business you own 50/50. You are willing to buy out your partner for $X. Your partner would have one of 2 options. They could accept $X and you would own the entire company or they would pay you $X and they would own the entire company. My guess is if you went into a negotiation with this type of mindset, a lot of the game playing would be eliminated and the price would be fair to all.
Have a great day!