The frequency of hitting big wins and how offen you will win depends mainly on the game's volatility.
I am not sure about Mahjong game but based on other users’ experiences, I tend to believe it’s a medium or high volatility game. The reason is because most users dn’t win so often but when they do, they win big.
What I wanted to say is that this has nothing to do with the name of the game provider as the same povider may offer both high and low volatility games. It’s up to you to choose which of them fits you best.