It's outdated guide, although the principle remains same. But i would recommend you to avoid cheap microSD or microSD from unknown brand, since it usually very slow or not durable enough.
Sorry you mean my guide is outdated? Or the other one for 3b?
Perhaps I should also revisit my guide when I have the time, regardless of it being truly outdated or not.
I mean guide on steemit which use 3B. Although yours could use update as well. For example, you may want to emphasize that Sparrow Server have no build for 32-bit ARM, which means your guide wouldn't work on 32-bit OS and very old version of Raspberry Pi.