Is OP actually proposing creating a two culture group system? As it's been done many times before, including by myself, in my proposal I just suggested it without separate criteria's but osme people have suggested having culture group and language group as two different "systems". Linguistic groups are sitll not, a valid category outside of academia and post 18th century nationalism. And wouldn't work anyway outside of europe and part of asia. Only with some of the european families, turkic, sinitic and arabic and a few other smaller ones to we actually have valid families of "these languages are close enough to be valid in some remote sense". So if it's kept realistic we'll end up with broken families like germanic, slavic, romance, arabic, towering over all else.
Hwever OP only suggests a map mode, but doesn't consider the linguistic ocmplexity of the world, how would caucasus be represented? burma? africa?