One might initially think that an en banc opinion by Judge Reinhardt that involved an analogous issue to Citizens United -- here, whether a city could permissibly allow only "natural persons" (as opposed to corporations) to sponsor an initiative petition -- would involve a close ideological split. Especially when that issue is combined with a municipal requirement that the official proponent's name appear on the initiative petition circulated to voters. After all, there's a First Amendment issue with respect to both requirements. And, remember, it's an en banc opinion. Presumably the panel did something that the en banc court felt necessitated review; e.g., didn't like.
That last part's true. The panel opinion (authored by Judge O'Scannlain) thought that there was a First Amendment problem here.
The en banc court does not. It's an 11-0.