The reason why the students travelled across the Atlantic was because there wasn't enough safe airspace for the students to learn to fly in. The training would have been given by RAF pilots who had been stood down from active duty. In sailing across the Atlantic the ships carrying the students were at risk of being sunk by U-Boats.
The reference to a high death toll, was more to do with the high losses sustained by Bomber Command during WW2 - not thru poor training - but because of the increasing competence by the German Ack Ack in shooting down planes. Statistically the new pilots had weeks to live, once classified as 'occupational'.
In effect I made a 'quip' - perhaps classifiable as sarcasm - even innuendo, maybe 'double entendre'. But it misfired as often this style of writing will do, if the humour is not shared. Not that there is anything humourus about WW2 or WW1 or indeed war at all.