Not really, I mean you can do it, but the results won't be like what your expecting
The grades during process aren't sifted from a single batch, they are manufactured to the specific grade.
When folks try mixing grades everything will work just fine for the first part of the experiment, but the finer grade will settle quickly to the bottom of the can.
That makes a variable in the charge as the mixed lot is used.
The olde tales of a "special mix" being used for accuracy has pretty much been defunct even in small scale local rendezvous shoot's.
"Mixing" is different then a "Duplex" load,, but with the small loads of a revolver, duplex is nearly a mute issue.
How many pounds of the suggested mix are you asking about?