Its not that far from what Oda's doing now. Ever since the timeskip the fanservice in one piece has gone up a lot more than you'd usually see
Although shonen jump doesn't allow its author's to work ahead of their established work rate(they have oda on an even slower pace now due to health concerns). I doubt Oda could do something like this without taking a break afterwards for like a month even if he was healthy.
Mashima could probably draw One Piece and do Fairy Tail at the same time if he had to he tends to do a whole bunch of work at once whenever he has to do something that might break his usual work rate.Oh and commenting on 340 zeref totally turned into sasuke good times ahead…....
Not really.. Nami and Robin had one bath seen each so far, the Sanji in Nami's body stuff and the Momonosuke stuff and that's about it and none of these are nearly as bad as what Mashima has pretty much every chapter