The amount of shock waves, black rays is exaggerated here, that's what I meant by ''visually''
Pageone is screaming in pain and his veins are jumping
Sanji hit him in the bottom, so he may have had an internal bleed. Gear3 hit him directly in the head
I think it makes sense for Sanji's attack power to be above gear3, especially if Sanji uses diable jambe.
Gear4 is more powerful than gear3, and Luffy still needed to hit Katakuri and Doflamingo many times to defeat them. Gear3 lacks decent attack power to defeat a character at the commander level, especially as an ancestral zoan.
The most possible event is that Sanji faces a calamity, a heavyweight ancestral zoan like Queen, so Sanji will have to have AP at least close to gear4 to defeat him