It mean most of his worker are combine of rank 2-4(and not 4 alone). In new update, worker 4-5 has more value. so you better scout for worker 4-5 and build fleet full of them, and not worker 2-3 inside too, better than his fleet. And he do not share price or details. And also the 36 worker fees.
Dev said a month ago, 4-5 star worker will have unique ability to get bonus stuff when new update roll out. And also just this morning dev said will roll out cosmetic, and selling land,... Lot of stuff going on. I have a whole fleet 1500mp, 3x rank 4 and 17x rank 2 worker. And I'm using.it to stack up a whole fleet of rank 5. Waiting for new update roll out and buying the land.