Backstreet Bouncers -- I have two of them in my humble Genesis collection. I tried to use them (and other relic/rune "hunters") for supplying Back-Alley Vendors but ... I gave up the idea.
Backstreet bouncer can also put a rune of strenth to hand --- Deception needs its own Choralis Rune Moth. I, as a Deception fan, envy the most about this card. 🙂
Dark knives/Selfless Guildmate/assasins aim - I tried to combine them but I couldn't make too many wins although some of them were epic. But much depends on your skills, play style and cards you have, of course.
Currently, I like using Whisper Barons because they, in some way, have Dark Knives included into them in case you play many Guild creatures.
I am experimenting with a deck with 28 Guild creatures. So potentially one of my Whisper Barons can get strength 29 😀 But this is only potentially 😀