I got into a long winded discussion on a Challenger forum about this exact thing end of last year. Guy posted a YT video on why bigger tires will stop faster but bigger brakes wont. I agreed with some of the video but the reality was that a 2015 Scat Pack stopped shorter than an a 2015 R/T despite being on the exact same tire. There is something missing from the theory and application doesn't match at some point.
To be clear, I'm not saying a single piston floating caliper is better than a 4 piston fixed caliper. I much prefer the fixed caliper setup. I'm just saying there is more to it than just the number of pistons or if it is fixed or floating.