"Too sophisticated" wouldn't be a way I would personally describe
Finlay.
But of course things may be different in Australia than they are in the USA. I know that in Australia to call oneself "middle class" is often thought to be putting on airs, while in the USA 95% of the population thinks of itself as "middle class." So by "too sophisticated", do you mean that in Australia you are afraid that people would think that naming a child
Finlay would sound pretentiousness or snobbish? Other Australians will have to answer that one! :)