Not many British managers or players take their careers abroad, but there have been plenty (certainly more than 5) that do so and most learn the language well enough to give interviews:
Venables (Spanish)
Lineker (Spanish)
Hodgson (Multiple languages)
Nathan Jones (Spanish)
Potter (Swedish)...
Seems very odd if that's the case and, I dunno, a bit disrespectful. I recognise that British tourists are probably the worst in the world for making minimal effort to speak the lingo when on holiday, but British players and managers tend to learn and at least make an effort even if they're not...
I think this is our man. Might need a translator for a while, Bielsa-at-Leeds style, but I'd imagine that he'll pick up enough English ove the next 6-12 months for this to not be an issue long term, unlike Bielsa who was such a genius that he still couldn't speak English after almost 4 seasons.