I found that although I followed the guides for Steem in a box 100% accurately, SteemD was repeatedly failing while syncing and nothing anyone suggested in the witness groups made any difference. The spec of the server was suitable and the kernel's version was suitable for Docker. I generally prefer doing things the manual way anyway, as I get to learn how the system functions rather than just pressing 'go' and backslapping myself for my genius. lol.
By building Steem manually and configuring the whole setup manually I was able to make the whole thing more tailored to my preferences, including taking the time to ping test each seed node and only use the ones with the quickest response times.