The involvement of the Giants actually has more implications than one would realize. Not only is one of the most powerful pirate crew that ever existed is siding with the Straw Hat Pirates but Elbaf is one of the few countries that openly practice the Sun God faith. Even Big Mom fears them and was going hooks or crooks in the past to gain their allegiance. Now that they found the human incarnation of the God they worshipped, imagine the threat this will pose to the World Government, having probably the most powerful race in the world against them.
Imo Elbaf being Nika enhances Little Garden in a really cool way. The warrior god they believe in thinks their battle/belief is stupid but protects the honor of both fighters regardless. Eventually its ended by realizing, oh damn we straight up got told to knock it off when they saw the posters.
It adds a layer of dramatic irony, that the viewer sort of has the first time around. The first time we know they're being stubborn and their god isnt real, the second time we know Lu-ffy is the guy they believe in, but we know he is just a human and his words still ring true.
They also promised to protect their honor, and the fake news that VP was kidnapped probably pissed them off. Once they saw the raid numbers they were probably already otw.