Unfortunately, 'code that goes together' is rarely "all these 3 things go together", but more "a and b goes together in one way, b and c in another, and a and c

Unfortunately, 'code that goes together' is rarely "all these 3 things go together", but more "a and b goes together in one way, b and c in another, and a and c in another. Meanwhile, c is more naturally contextualised as d, which has nothing to do with a or b, so it should really be close to d and far away from a and b, but somehow still close" etc etc ad nauseam. So, really, the only real way to keep functions linked is to not be lazy, and try to have proper documentation locally in your function which includes a "see also" bit.