I'm orchestrating a piece and distributing a chord among 4 bassoons.
If I were writing the French Horn part, I'd know one of the common practices would be to have two staves: one for Horns 1 and 3, and the other for Horns 2 and 4. Does the same splitting scheme typically apply to Bassoons or other instruments?
French horn is the only instrument that is traditionally split 1-3-2-4; everything else is going to be in order from top to bottom regardless of how you split up across staves.
As far as conventions for staff usage, a lot of that depends on the overall instrumentation. The standard for symphony orchestra scores, generally, is no more than two voices per staff. At the same time, lots of modern wind band music is so complex that publishers prefer to typeset only one part per staff.
Mostly, though, you just need to be consistent with the rest of your typesetting. If you're writing for a gigantic Mahlerian orchestra, you may need to economize just in order to fit all the parts on the page, and change distribution based on the needs of the music. So chances are, a simple chord in four parts is going to make the most sense on two staves, 1-2-3-4, but we can't really say with certainty unless we know the context you're working in.
