I'm surprised there isn't more commentary on when and how to use external but standard or common commands like grep, sed, awk, perl, join, find, tar, parallel,

I'm surprised there isn't more commentary on when and how to use external but standard or common commands like grep, sed, awk, perl, join, find, tar, parallel, etc. It's one thing to use bash consistently everywhere but as a heavy multi-machine shell user I've been bitten by incompatible or missing external utilities more often than I care to admit. You might be surprised how many systems aren't using the GNU utilities, have them running in a weird mode or are using ancient versions of them. Maybe Google is religious about keeping all their environments identical?