Luffy? Definitely. Zoro? Not at all. Zoro hasn't done anything super spectacular that sets him above Sanji since the timeskip.
That's actually the best possible kind of training for Sanji. What matters is not their teacher. Just because Rayleigh is stronger than Ivankov doesn't mean a student of the latter got inferior training to the student of the former. Strength isn't vicarious. Luffy's training is only as good as Luffy is. Same as with Zoro and Sanji. The gap between Zoro and Sanji wasn't that high, so the quality of their training wouldn't have that higher a gap either.
Training where Sanji is running for a year is the best kind of training he can get, as his fighting capabilities revolve around his legs and his speed. That kind of training is gonna boost his strength dramatically.
Again, Luffy, sure. But Zoro hasn't displayed any feats that suggest this. Even then, raw power isn't all it takes to win a fight. Even if Zoro has island busting abilities, there's still durability, speed, stamina, and yes, intelligence, that all play a role. So while Zoro can drop mountain-cutting slashes and Sanji can't drop mountain-busting kicks, that still doesn't mean Sanji can't withstand them. It doesn't mean Sanji can't avoid them with speed. It doesn't mean Sanji can't gravely injure Zoro. Area of effect also doesn't necessarily mean stronger. Zoro's flying slashes are his power spread out throughout an area, while Sanji's kicks are his power in a focused, precise strike. It's fully possible for Sanji's kicks to pack the same overall power as Zoro's slashes, and have a smaller area of effect.
One of the grievances about Sanji expressed in this thread is how his performance appears lackluster in comparison to Zoro. This is argument. By substituting Zoro into the same situation that Sanji was in, and seeing how well Zoro would have done, which isn't much better, it dismisses the notion that Sanji's performance was lackluster in comparison to Zoro.