Speaking as an Aerodynamicist you seem confused.
What has velocity got to do with Car A and Car B being driven the same?
What has powerplant/regenerative braking got to do with the fact all vehicles do or could have the same system?
The drag equation is:
D = 1/2 x density x wetted area x CD x V^2
Since V isn’t changing (both vehicles being driven the same) it is irrelevant, as is density.
For drag coefficient (including form and skin friction), and a quick google as to numbers (apologies but in haste), suggests 0.3 for cars and 0.35 for SUVs.
Wetted area, in this case frontal cross section is apparently about 3m^2 for a SUV vs 2.3m^2 for a large saloon.
So comparing gives you 0.7 for a car and 1.05 for an SUV.
For context cars vary from CDs of 0.2 for a and Areas below 2.0m. I picked larger ones as these seem the logical comparison to SUVs but this shows cars themselves range from an indicative force of 0.4 to 0.7, (c.75% increase). SUVs compared to the larger cars are a c.40% increase.
I remain to be convinced this is significant when all the real world factors are included as for all the noise, I recall a car aerodynamicist telling me their job was to work out and try and improve the marketing/designers shape - rather than produce something aerodynamic and that they only mentioned if a PR angle was required - aerodynamics being not the driving part of efficiency.
The reality is, despite having a hatchback car, I do love the high up seating of SUVs, mainly for the view over all the road clutter and surroundings (not so much over other vehicles). I also drove slower, I assume due to the sense of cornering forces.