I think we've missed a chance to make this *more complicated*. For example, in a partnership that's got "fixed" percentages, but pays its partners guaranteed payments for their services - based on something other than the fixed partner percentages - there's always the possibility that the partners agree to give the partners a "kicker" to help them pay their taxes on their partnership income. If the kicker is paid as a guaranteed payment, then the complications begin...!! I could go deeper into this morass but I get confused when I try to think and type at the same time.
e.g. two partners are 50-50 in ownership of a business, but one partner's working full-time for the partnership and one's either wealthy or retired or lazy (or all three, but why identify myself so carefully) and only puts in a few hours a week. However, the wealthy, retired, lazy partner is just making sales calls, while the "full- time" partner handles all the administrative crapola in addition to being in sales, too. The partners agree that their guaranteed payments for any year will be a combination of an hourly wage for the admin partner's time spent "in the office" plus a "commission" on the sales generated by each partner, plus a "kicker" to help them pay their taxes. End result: the partners are 50-50 but their "tax kicker" won't - not by design at least - be 50-50, but since it's paid as a guaranteed payment, it's deductible 50-50 even though it may be paid out in any ratio that the formula determines.
What the formula would be for the tax kicker, well that's an entirely different story, it'll be in the next chapter of my upcoming book "Real World Solutions to Nagging Puzzles in Flow-Through Entity Taxation".
[footnote: when the "worker" partner approached the "retired" partner about this "tax kicker" payment the "retired" partner (the rich lazy one) said something like "Well, son, you just pay your taxes like everybody else does, by writing a check to the gummint." Then he was reminded that he was rich and retired and lazy, and the other guy really had to make it on what he could earn from the partnership. They agreed on a formula for a deductible payment to each of them "for taxes". One that wouldn't deplete their capital accounts unsymmetrically.]
Just kidding about "my upcoming book"...