I disagree in FPL. Grealish has started every game, blanked 4 times, and got 1 goal and 1 assist in 2x 5-0 routs. If KDB had played all of the minutes that Grealish has history says he’s getting more returns than that.
Then there’s also that you can’t shuffle Grealish to anyone. He has no players worth having around his price. I own Jota and whilst he is starting I would rather play him than Grealish.
The reason to move to KDB is to shuffle around with Mane and Bruno, and take on Lukaku. Grealish isn’t capable of that imo.
Last year they played roughly the same minutes and got roughly the same returns.
Both will likely eat into each others pts as they share duties this season.
Given Grealish is 8 to KDB's 12, I'd rather get almost as many pts for that MID spot, then make the cream by utilising the other 4 units by getting Cancelo and / or Dias.
As for KDB to Mane or Bruno, I don't think that's an option. Salah is the big gun for the MID spot.
As he takes PKs, you'll prefer him to Mane, and Bruno is no longer an option with CR7 in the side.
As for Kane, Son is better value, and he can be toggled with Grealish.
For me, it's Son + 4.5 DEF or Grealish + Cancelo / Dias.