>>28544348He has a point. You're more likely to remember gym leaders you saw a lot playing through the games.
If I had to pick a game that had the most Gym Leaders I remember, it'd probably be Gen 3, because I played the fuck out of that game.
However, BW had the gym leaders involved in the plot so you got to see them more, making them at least a little more memorable than some others.
I barely remember the XY leaders, but that may be just because I blew through that game and haven't went back to replay it yet.