There are several autistic polyglots including Vaughn who are incredible. And Richard Simcott is in their league i.e able to obtain native like fluency and accent, though he is very modest about his abilities, putting it down to his love for languages. Steve Kaufmann has stated that he aims for clear communication not perfection.
Incidentally, when most of us are asked how good we are at something, such as driving, almost everyone says above average. I’m in the top 5% at maths, that’s proven by exams, but mediocre at sports and language. Hard work can and will compensate, as you suggest.