Again, we need to start the rebuild with the first Shero draft, which was 2016.
I'm going to expand upon this by saying 7th round picks who don't make it are not necessarily bad picks. For when he was picked, Davies was an excellent selection because he was a Nashville trade target and made the AHL.
Finally, we need to consider what defensemen were available when criticizing a pick. This is to say, it's tough to critique picking Reilly Walsh in 2017 unless you can find a defenseman who would have been a better pick to compare against him. Now, I'm not exactly in the Walsh fan club -- I like a steadier defensive presence in my own preference. However, we also must factor in that Walsh was taken at #81 overall in a draft where there is exactly ONE defenseman who looks capable of being above-average at the NHL level (Mike Anderson, #103 overall to LA).
In 2018, we can look at the Ty Smith pick critically, because a much better LD was taken later in the first round in K'Andre Miller. Those who follow me know I actually ranked Miller higher than any other draft ranker in the continent, rating him as a viable top 10 pick. But we also should temper my own criticism by mentioning that Smith's consensus ranking was in the 10-15 range, while Miller's was probably 25-35.
I'm also going to say there's no "who" for Zaitsev or "who knows" for Misyul, because to be frank, I know. Both of them are viable NHL prospects as defensive LD for a bottom pair. As such, Misyul was a good 3rd round pick and Zaitsev was an outstanding 7th round pick. Particularly with Zaitsev, he was picked #205 overall, and out of every player available he has enjoyed the best pro career, though obviously it has thus far been in the KHL. Either way, good pick. With Misyul, it's a bit murkier because there were a few D drafted after him who would probably rank a bit higher right now, like Spence and Thrun.
Speaking of the 2019 draft, you also omitted our #1 RD prospect in Case McCarthy, who was an outstanding pick in the 4th round and remains on track to be a physical, defensively sound bottom-4 guy at the NHL level.
And of course there's Luke Hughes -- who is currently in a five-way battle for #1 prospect on the planet along with Byfield, Power, Beniers and Sanderson. If we stick with the 2020 draft, Mukhamadullin also looks like a sound, if not spectacular, pick at #20 overall. He's still a 1st-rounder in a re-draft, though I'd probably slot him slightly lower, in the 25-32 range.