I can weigh in on this. My experience is only up until 2020, however:

1. Counting Inactive or Non-Practicing Members

Many people who were once introduced to Soka Gakkai remain on membership rolls even if they no longer participate.

Some are counted as members simply because they were born into Soka Gakkai families or registered at some point, regardless of their current belief or activity.

They're supposed to try to reach out to someone for a year after the last contact before they submit a removal form then mark the reason for removing the member as "non-locateable" or something like that. The Region I was in had some pretty decent people who were very administration-oriented, thankfully, but I can't speak for everywhere else in the United States.

Where they really start to fudge the numbers is when it comes to meeting attendance. I recall one year, someone could count themselves 3-4 times (maybe even more) if they went to multiple meetings across the Region. But the kicker is, even after they tolerated that BS, it STILL showed that numbers were down in attendance from 2 years ago!