In my opinion this statement i.e. “Having one well-developed language was superior to having two half-developed languages” is right.
It is a right statement because one well-developed language that can be used for many purposes such as speaking, writing etc while on the other hand, two half well-developed languages have no use in writing and speaking due to its underdeveloped. This type of language can't be used in writing and speaking so that's why in my opinion one well-developed language is better.
