Once japanese and chinese stuff is removed I'll understand strict banner rules to preserve thematicity. Until then if it's for an obviously existing clan, not generally considered hateful or nsfw, whatever, add it in. The people who actually consider it hateful or something are a small minority, unlike the people who'd be bothered by a chocolate chip cookie flag (also could that make the banner pack illegal in Germany?).
Not that the japanese and chinese stuff needs to be removed, it's just that being strict with thematicity in one place and allowing completely out of place stuff in another place is pretty stupid.
Also the USA banner looks awesome