I think a high end haki overflow three swords style move vs 3 low end hits from G5 should be comparable imo. Especially when you take into account that Luffy plays around a lot and doesnt always go for the kill like Zoro.
Because like I said he couldve went for this punch from the start:
And just KO Lucci temporarily as per canon but Nika will goof around, its what led to that whole round 1 debacle with Kizaru and now hes 1vs2ing him and Saturn because hes more serious.