To clean up some of the misconceptions around the wonders of dual charging I attach a table of the theoretical maximum charging to expect given a certain connection. The connections are the ones you find in "the wild" in Germany. For you own country, assume that single chargers can do 3 phases with 16A max. Or 1 phase with 40. Dual can do 3 phases with 32A max. Or 1 phase with 80A, but I doubt that you will find more than 32A or maybe 40A because of the cables required.
Single, Dual 3,7 kW
Single, Dual 7,4 kW
Single, Dual 6,4 kW
Single 6,4 kW, Dual 12,8 kW
Unless anyone proves me wrong that means that dual charging in Germany only has a benefit if you have a 400/32A connection. For everything else, incl. 3 phase 230V/16A, a single charger does exactly the same.
And, none of this numbers is 11 or 22kW.