Ki-27 vs Ki-43: Why is the Nate tougher?

[JG53Frankyboy]

at least the Alpine Fighter Collection's Ki-43-I in NZ had a tripple layer of rubber and silk "protection" for its fueltanks. but true, its a very late production Ki-43-I !!

my "concern" about the 43 and 27 in DM comparison is how easy it is to flame the 43 and how difficult the 27. Even when it is very easy to get a fueltank leak and loosing fuel in the 27.