Einstein and Feynman were both nobel prize winners and Hawkins has Sir Isaac Newton's mathematics chair - we probably shouldn't downplay their achievements!
Carl Sagan was on the slippery slope. He certainly did some good science - but he's hardly up there with the previous three. Tyson has a few decent papers to his name, and his career isn't over yet - but I don't think he's coming close to the others in terms of science achievements.
Einstein was the world's worst communicator. Feynman and Hawkins are better - Sagan was astounding and Tyson may be yet better.
I suppose we might be concerned that there is a pattern here. We're taking people who are better communicators in preference to those who really know their stuff.
But honestly, does it matter? The presenter of a show reads from a script - (s)he is basically an actor. If the author of the script sticks to an accurate portrayal of what's written by the hard-core scientists - then why not pick an engaging personality to present it to us?
The critical part of the cycle is the person who decides WHICH science gets discussed. De Grasse Tyson is often talking about tacheons, wormholes and white holes and other claptrap that's horribly speculative, wildly unusupported, and very probably untrue. As an astrophysicist, he should know better - but as a TV presenter, he does a reasonable job of reading the script.
I'd prefer to have a complete non-scientist who is a supreme communicator be given a script written by good script writers from material handed to them by the hard core scientists behind the scenes - than to rely on a lower-tier scientist (or a high-tier scientist with poor communications skills) to do the entire job.