When you measure in litre the scale increases, or rather gets measured by equivalence in other country's "standard." Most aro keeper i know overseas for asian is average 240 litre. That's 65 gallons so yes, it's funny how the "standard" gets overlooked when you compare to skill level, or just plain & simple a different style of fish keeping. Bigger the tank not necessarily the better, but the better the fish...tank size gonna get questioned. Keep a sturgeon in a little pond vs keep a big ass dog in a little bitty backyard, Same same same.
If u can rock an asian aro in any tank that it'll eat in & stay healthy in, who cares where u live just try not to compare your style of fish keeping in respects to those that keep perhaps the opposite style. Make it your own + love your fish that's all that matters. Seen bad ass aros in tiny tanks that'll fade some monster tanks any day.