Honestly quite a lot of discussions I've seen involve people trying to justify the numbers to their own convenience. My experience early in the season was pretty weird as well. I got 3 players:
A: NT player with average stats, nothing on the leaderboards
B: NT player, constantly 1st in scoring, top 5 in assists in the league.
C: Non-NT player, top 3 in rebounding and top 5 in assists (was 1st for a period) in the league, 1st in blocks in the country.
Earlier in the season, even when A played in NT games and B didn't, C would still earn the most while A would earn the least (among the 3). Based on what I read, people were saying that leaderboard stats were weighted heavier, so it made sense.
But right now A is earning the most out of these 3. His jersey sales came out of nowhere - no stats on leaderboards, still a NT regular... In fact C (who earned the most) got into the NT and didn't get much of a boost (I'm not sure if his sales dropped tho, it might have). How do we explain the change? All factors are more or less similar, there shouldn't be such a big swing.