User blog comment:Toshiroichigo/Bleach villains/@comment-5551986-20131103094927

He is an artist, so he may have particular preferences when creating characters with certain themes, he wouldn't exactly create characters and factions that are out of his comfort zone or that he dislikes to draw, its his story, his work, he can tell it and draw it in whichever way suits him.

Besides, not every character in every faction is a specific theme. Look at Cang Du, he stronger resembles someone from Chinese/East Asian Kung Fu culture, you can see this by looking at his clothes, fighting style and facial features. Although Quincies strongly resemble this there are quite a few like Bambietta and friends who don't follow the motif, I think this helps differentiate between characters and help create a personality for them.