He created a gigantic forest which turned entire Udon Prison into vines.
And additionally they were cripples.
Marco is in the same ballpark as King/Queen and see how he performs.
G5 is made for Luffy to fuck around and to allow the author to sandbag him. Its abilities range from ~ base Luffy lvl to much, much greater than KKG.
The thing is Luffy is neither using his impressive Haki nor the impressive aspects of his df awakening and Lucci's already seeing stars.
This was a given.
The "Lucci can keep up with G2/3 Luffy with CoC" is bollocks.