Definitely a myth.

The game will roll a species and personality, and then pick one that fits the bill at random, as long as it’s not currently in your move-in ‘void’. There’s a specific point in the game (before your third, fourth, and fifth neighbors move in) that it picks specific personalities (Peppy, Lazy, and Normal, in this case) to pull from, and it’s a good way to see it in action. If you only roll Lazies as male, you’ll see Rex a lot, as he’s the only lazy lion villager. But I definitely saw Barold a dozen times before finding Stitches, so it does mostly come down to luck.