Is that about Zoro and Lucci's fight? Ok: Lucci did not fully go all out on Zoro, because he didn't try to kill or hurt Zoro, but held back - Zoro was a means for Oda to stall Lucci.
Because, Lucci is fully on the side of the SHPs. The only reason why Lucci attacked the Stellar was to get rid of Stussy, who is still working for the WG. And the only reason Oda chose Zoro to fight Lucci is because only specificly Zoro is able to stall him - not because of his fighting skills, but because if Lucci was to leave Zoro alone, the samurai would definitely get lost. And because Lucci is on the side of the SHPs/Vegapunk, he cannot let that happen. The SHPs would need to go search for Zoro and lose time they need so desperately to flee. So, Oda used Zoro to stall Lucci.
Lucci needed the SHPs to believe he is still the bad guy, because he wants to be left behind. This is the second reason he attacked Vegapunk. If the SHP were to think that Lucci was their ally, Luffy would not allow them to leave without him. And Lucci needs to stay back and sacrafice himself, because we have Kizaru, who is able to bridge the distance between Egghead and the Sunny in a moment even if the SHPs are able to leave the island. Someone needs to stall the admiral, because their plan is flawed.
If someone needs proof - I can give them that.