In polymetre and/or poly-tempo music, measures count in staves may be unequal.
How measures should be numerated?
Each stave have separate numeration?
Music: Practice & Theory Stack Exchange is a question and answer site for musicians, students, and enthusiasts. It only takes a minute to sign up.Sign up to join this community
The purpose of measure numbers is to refer to points in the music, for example in rehearsal. In polymeter music where bar lines don't line up between staves/parts, it's hopeless to try to refer to a point in the music by measure numbers.
Use rehearsal letters where things do line up, and don't number the measures at all between them.