I believe you wished to ask if SAP MM/SD is a better combination than SAP MM/PP or the other way around.
I’ll tell you what, you should learn all the three! SAP PP/MM training course and SAP SD course. Once you know all the three modules completely, you'll be able to be an excellent supply chain consultant!
As straightforward as it sounds, it'll, however, take you a minimum of 5–6 years to learn all the three, with enough hard work and dedication, only if you have relevant opportunities on the job.
Quick video for you to get the gist of SAP MM if you are new to it: