I am in the middle. I think that what rohen and jkid20 mean is that trying to target the whole spanish speaking community can be tricky since there are many different dialects and what it works for mexican spanish it doesn't for colombian. The french speaker community is not as spread out as the spanish one and copywriting wise there are less cultural nuances to take into account.

Having said that, it has to be admitted that this is not a proper SEO issue but a usability concern in order to convert efficiently or a matter of linguistic localisation.

I would say that chinese is quite a complex language to optimise for as well as russian.