The only way that someone can shoot those scores with that few rounds is if:
1)It's a 2nd account and the player has played previously under the original account
2)The player was playing under someone else's account, and finally created their own account.
3)The player is using a cheating aid
4)The player played a ton of practice rounds prior to posting ranked rounds (or has played a ton of ranked rounds and only posted their best scores)
It is practically impossible for someone who just started to play this game to post scores like that. It doesn't matter how good they may have been in other golf games. I've been playing some sort of golf game for well over a decade, and I didn't post scores like that when I first started at WGT.
I may have bought it if the scores were at Kiawah and not BPB, but not only were those scores posted at BPB, it was with the default clubs (though I did see 1 upgraded club in the bag, a tour starter at that).
Now, I'm not saying that the person is a fraud. But the only way those scores are possible is if they meet 1 or more of the 4 points I made previously.