I'm not underrating the live floor at all. There's a few fights i'm interested in (mainly Jinbei vs Who's Who and Franky vs Sasaki), but it still impressive the power creep / power up from the Straw Hats to take on the F6, especially without Haki.
So yeah, it's a bit hard for me to see Sanji taking on King 1v1 and Drake taking on Queen 1v1, and Marco being dealt with somehow, Marco is fucking powerhouse in this area and there isn't many people that can hold him, King being the only one besides Big Mom and Kaido imo, even Smoothie wouldn't be able to deal with him at all.
Also, if Marco healing was this OP and useful on the roof, he would've healed a lot more during Marineford, at least those cuts and bullets that Whitebeard took.
But yeah, could happen, Drake is a Captain of Sword afterall, he has been portrayed above Koby and a few of them at least, even if Oda is already hyping up Koby. The other part is that Sanji is already looking pretty damaged and even was KO'd according to Lebrent, so him taking on 100% King 1v1 is going to be really fucking tough.