Just going to take a stab guess.
in other games, contact range would be controlling factor for effects or behaviors/eg a fleeing frog in FFIX would run based on rules inside contact range, or lets say object starts floating when in contact range, then 'talk range would be the controlling setting for activating it(capturing frog, activating floating object)
where they can be set depends on how the code was made I guess, init would usually be set after main(as a C/C++ example), this however when in regards to many script implementations seen in other games, init is the first called, then main is called as the primary setter.
regarding Cloud, is it possible that the order of calls to the script is
init - set some values
sets other default values(assuming contact range is set based on parameters, one which could be as you said, model size)
main - rest here to override defaults
I have no clue about any core stuff in Final Fantasy games in this degree, just thinking implementation wise seen in other games which has had source available.
and yes, this sounds like a horrible way to do things, but hey, lots of games has really weird code running around in them.
