Are you familiar with Layers in Finale?

There are 4 Layers:

Layer 1, Layer 2, Layer 3, Layer 4.

Are you familiar with the Speedy Entry Tool feature {Voice 1 / Voice 2}?

In each Layer you can have 2 Voices, giving a total of 4 * 2 = 8 simultaneous rhythms in the same staff.

For most choral work, it's pretty unusual to need more than two layers in a single staff. If you have something like hymnal staves, JW Staff Polyphony is a Godsend (no pun intended.)

In treble staff, I would assign sopranos to layer one, altos to layer two, and then, in the bass staff, tenors to layer one, and basses to layer two.

I  find it easiest to break the chorus into 4 staves, to best separate them for learning tracks for the singers. In fact, at this very moment, I'm working on a chart with 4 staves, broken out to 8, for S1, S2, A1, A2, and so forth.