Mr Chips made no such allegation or inference. And there is a difference - to have studied to A-level standard involves competing those 2 years of education post-GCSE or whatever quals English schools give out these days.
Of course ATSAs can be extremely intelligent people, and I know of one working on his second OU degree. It's a pity that NATS no longer wants to pay for ATSAs, at least at salaries of those on old contracts.