Minidenticons are complex to manage at UI level, they clutter up the profile, imo.

WoT (first) + pet names are a good enough solution.

Another quite easy solution is to add an index (it could also be a component of the WoT, @hodlbod?) that counts previous interactions (replies , reactions, zap) that you actively had with an user. This prove immediately that you are facing the real one. 

 Yeah, follows are just scratching the surface of emergent WoT 

 emergent WoT.
it sounds like a creature with 74 arms coming out of a swamp 

 But nice 

 “hero, I am WoT”