Polish engineers are sometimes a bit late when it comes to the new technologies, but are very good compared to ones from, for example, Ireland.
It doesn't matter. They are no smarter than BA's original British engineers, but with decades less experience on those systems. Even if they were smarter - and in general the talent prefers to work for real companies, not bodyshops, so that's unlikely - they can't compensate for the lack of real experience.
Only a person who believes experience doesn't matter would sign an outsourcing deal.