the poll itself is who is the best from a support, vg and assaulter.. no answer to this :P
You can't compare a supporter with 2 assaulters.
So lets leave Shin Urahara out and compare between Hirako and Shin yourichi.
In PvP + PvE Shin Yourichi is definately better than Shinji Hirako because she does more dmg, has better stats and she can be immune to all attacks for 2 rounds.