If you're worried about economizing on the number of cuts it may be that you're doing the cuts wrong! Fix the miter saw to something: a work bench, a plank, a pair of the 12+ foot 2x4's you'll be using for top plates, etc. Now fix a stop block to that bench/plank/etc at the correct distance from the saw blade, and one short block near the stop to support the piece being cut. This jig will take 5-10 minutes to set up and will accelerate the cutting of the wall studs. Viewed from the front with a 2x4 laying on the saw and support, flush up against the stop block on the right, would look something like this:
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A tall stack of top/bottom plates isn't stable (it'll easily roll forward or back), doesn't inherently give you a nice finished plane for affixing the drywall, and is just plain heavy (at 16" center spacing, you'd have 10 pieces times 16 inches = 160 inches of plate doing the job that 12 inches of wall stud could have done).
Also.. think about the time you're going to spend nailing all those plates together, and especially what a nightmare it's going to be every time you have to bore through that stack to run a wire or pipe between the wall and ceiling spaces.