The question is whether the strength is necessary. Now I don't know much about the type of plastic or construction of the Heng Long Leopard, but I have the AFV chassis inner brace on my Tamiya Leopard, which is similar to what you have made for the Heng Long hull, but my Leopard is no more and no less reliable than the several other Leopards in my club running without the inner brace kit. All it does for my tank is increase its weight and possibly affect its acceleration performance and run time.