I would keep 3, which would be one side of nest boxes.
I think 8 birds with this coop is pushing it due to overall amount of usable floor space as well as feasibility of putting enough roost space for the number of birds. You may need to shrink the flock a bit as they grow up, but that's something you can play by ear as the birds grow up, since you seem ok with rehoming birds if the need arises.
I'm making it easier on myself selling my extras buy using the money from the sales to buy this year's chicks.