Grande gets four of the half pumps. The shaken espressos are designed so that they get the same number of pumps as a usual drink, only with the half dose sized pump. So you’re on the right track, but you actually have to go the other direction. If someone orders a grande brown sugar shaken espresso with, for example, white mocha, the standard amount of pumps would be two instead of the usual four, because white mocha uses full dose pumps

The shaken espressos all get half pumps unless otherwise specified, think about this way, it helped me never forget they are always half pumps, so you know how much ice they’re getting (just about the cup full with space for a splash of milk), it would be way too much sugar if it were full pumps since there is a little liquid which is unlike a latte which makes sense that there is full pumps. I hope this makes sense!