The braking technique described by A and C is the same on the 737 so i guess boeing and airbus agree at least on that piece of operating a jet, or my company did try to get the same SOPs on all fleets which is of course possible.
However accelerating to the max recommended taxi speed of 30 kts and then smoothly braking almost to a stand still and then accelerating again is only possible if there is no one in front. If there is the a slow moving aircraft in front the acceleration intervall between braking becomes so short that it is pretty much the same as riding the brakes. Therefore extremely slow aircraft can be a real issue.
It would have been more professional of course to ask ATC for a way to overtake the slowpoke instead of venting like that. Even though BCN is pretty simple to taxi along if you made yourself familiar with the airport beforehand. An moving airport diagram with your own position of course helps in situational awareness but is not really needed.