And Luffy, King of Prodence, Don Chinjao and Zoro aren't Vergo. Vergo lacks the scale to destroy that golem. It's like Smoker for example who has great movement speed but lack scales(his arsenal being limited in punches). I don't know why you keep using examples of others as if they were Vergo. No they aren't.
Chinjao+King of Prodence destroyed the arm of the golem with
1- A continental buster attack
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2- A lighter version of an attack capable to destroy a fortress or even KO a yonkou by hype(though i doubt it)
Luffy's Grizzly magnum is mountain level buster, so is Zoro's 1080 Pound Phoenix
Vergo simply lacks the area of effect in his attacks to replicate what they did
Zoro can cut steel since Alabasta, but alabasta Zoro can't cut that golem. You keep repeating this as if the material durability was the problem. No, the problem is the scale. That golem is
too huge for any attack Vergo ever displayed. You're comparing a mountain level scale to a building level buster
Besides what is he even accomplishing by doing that against something that will regenerate anytime soon?