Moncada hits the ever loving piss out of the ball and he's becoming such a good hitter that even when he's not squaring it up, he's getting hits.
His BABIP is always going to be an extreme outlier. He's just that good in EV and as a hitter.
The way I look at it is that Robert is always going to put up bigger power and WAR numbers but Moncada is going to hit for higher average and slightly less power. Moncada is going to be in the 25-35 HR range, and probably hit .300 regularly with a .360+ OBP and Robert is going to be in the 30-45 HR range and hit .270-.285 with a .340 OBP. Robert's BA could be inflated a bit by his elite speed. I continue to be baffled by Moncada not running as he has the ability to steal 25+ bases.
They're both great players.....but Robert is at a different level, especially if Moncada isn't going to run.