I have NEVER met or heard of an FO at Ryanair who has done 900 hours between May and the end of April. I did 730 according to my logbook. I think my second year was about 100 more. I've worked in both large and small bases...
It may happen in very rare cases. New cadets are ten-a-penny and there is no need to work them hard. Add to that the fact there are delays caused by line training and base changes, means that 900 hours would be rare.