I'm probably in the opposite camp when it comes to Clarke. I wasn't super excited about the pick, though the players I was hoping the Kings might pick up were already off the board (Johnson and Edvinsson). To me, Clarke seemed too one dimensional and more of a PP specialist than even a middle pairing defenseman given his weaknesses. I also questioned his attitude as he came off, in my opinion, pretty arrogant and immature. Since joining the NHL, though, I have been impressed with how much he has grown and how hard he works for it, and really like that he is able to get under the opposing team's skin. His skating is still a big weakness, but I think he can overcome that with experience and be a solid middle pairing D who excels in critical moments (PP, goalie pulled, shootout). On the flip side, I was super excited about picking up Pinelli in the second round that year who, so far, has been a miss.
Byfield still looks like a future L1 Center to me, and Turcotte looks like a future L2/3 Center with his size/strength playing a key factor. At worst, I can see Byfield becoming a solid 2nd line 2-way center, and Turcotte becoming a 3rd line faceoff specialist (which worked out pretty well for Stoll). I don't consider either of those picks to be misses.
Greentree is another solid prospect with skating concerns. I do agree with you that our prospects seem to all be a bit niche, which isn't optimal but can excel with the proper team composition and strategy.