I guess SB in just one player is unuseful.
I don't usually like to just pick out a small part of someone's answer but in this case I don't disagree with you, I just didn't make myself entirely clear in my answer because I was replying too specifically. I completely agree with what you say in this quote, but I'd quite like all my guards to have SB too. Certainly one player with SB will leave your opponents picking on the player without it.