I'd say Easy and Ryan between them would account for more than 20 737 jobs a month ... however as a-h pointed out, they have their own type rating schemes which I'm sure earn money for them just like the Astraeus one.
If I was to go buy a rating then I would at least do it with a company like Ryanair that has dozens and dozens of 737s and a realistic shot at employment at the end, as opposed to Astraeus which cannot possibly offer work to more than a tiny percentage of their trainees.