No, they do not. Or at the very least you should not draw conclusions like that. How do you corelate language skills with technical abilities? There is large group of people who even with perfect language skills is unable to shake off the accent as it is probably genetics/biology. Thats why you hear accent in "foreign" people after 20+ years.

Please, trust your intuitions little less. Treat more of your impressions as anecdotal :)