From a user experience point (it would call this a fundamental flaw 'in a race') you could quick fix this by making it for the time being Asia vs Asia, Europe vs Europe, etc. That should not be to much of work for the devs imho.
Then for the long term you can discus the alternative options and make a long term discission (and please let us know then when you made your discission).
unfortunately that's not a solution as clans are not region based (you can be a US based clan with chinese members etc).
there isn't really a 'quick fix' for this specific timezone situation