I admit, when I read “Italian Soundtracks”, I tend to go by composer, but of course Italians have written music for non-Italian movies, and non-Italians have written music for Italian movies. (I usually go by composer, but of course, that’s but one option.)
I agree, that’s a plausible way to look at it.
By the way, stylistically I find Marianelli’s most italian score is The Boxtrolls, which is one of my favourites of his.