a tree with 6" diameter yields 4 staves.
but if you mill it into 7/8" boards, you get 6boards wich yield 1-3 bows each.
it's no shame, it's just 250% more efficient
but... A lot of work and knowledge is involved in making a standing tree into a ready-to-go stave. With boards, you just pick the straightgrained one.
Boardbows are great and quick, wereas stave-bows require a little bit more skill and work.
Nick