Solar Auxilia plays differently from the Legions, but the list is made to tear them a new one something fierce and not an afterthought.
They may not have Rites of War or Primarchs, but they do get some of the better rules built in, like overwatching on BS2, holding hands for +1
WS and well, being able under the right circumstances to field more tanks than the enemy.
And yes, the Dracosan is a filthy Rhino-Vindicator hybrid on steroids.