Mr. Bergman hit it exactly right. In order to maintain the same
clamping force, you must maintain the same square inches of piston
area.

A couple of other comments. The goal is to provide maximum moving
friction without locking up the rotor. In order to do that, it is
important to keep things "consistent."
Even loads across the brake bad, lack of flexing in the caliper, lack
of cocking, angling, digging, or otherwise flexing of the caliper and
its loads in relation to the disk are important.

When all done, race cars take advantage of every little bit they can.
Braking is very important. Race cars spend a lot of money and weight to
keep their calipers and pads true to the rotors.

Flexing is a bad thing, and floating calipers by definition must move
about to do their jobs. Single piston calipers are not as good as fixed
calipers.