As we all know, the the salaries are partly a function of when it was that people signed their contracts, with outcomes different from the potentials that were anticipated at that time. Also, historic GT or other famous winners and team leaders (not just Froome and Sagan, but also Nibali, some others) probably demand more because their name recognition and their effect on the team helps even if they are no longer winning races.
But still, there are some surprises. I would not have guessed that Fuglsang and Bardet would be in the top 20. Bardet was on the GC podium at TdF twice 5 years ago, but
AFAIK, has never won a major stage race or monument. Kwiakotski has had some great results, but his world championship was 8 years ago.
But one thing to note is that after the top 5 or so, the rest have salaries quite similar to one another, and I'll bet the next 10 (#s 20-30) are all pretty close to these.