Assuming the classifiers are known before hand, its pretty easy to figure out how fast/accurate you need to shoot to make X classification since the result you need to get is known.
Lets use CM 18-04 (30 pt stage) as an example.
Shooting all Alphas, to make B you will need a HF of 3.7516 which means you will need to be able to do it in 8.00 seconds. Now go try that in dryfire. Now you have a baseline/feel for what is required. Don't think you can shoot all Alphas in 8 seconds? lets say you are going to shoot all C's (MAJOR) for 24/30 pts. To make B, you have to be able to shoot all Charlies in 6.4 seconds.
My biggest issue with classifiers is that i felt like i need to shoot fast, without ever knowing the math of what i need to hits/time. Once you can quantify what you need to do for the expected results you want, then "all you need to do" is drill those in dry/live fire.