Well, the problem with that is each Cultist put in is effectively +1R, but better because it could be a combat unit too. That more or less makes your unit 1R for 1/2/2, which is just really great. However, there is a deck balancing factor, as to lever those cultists without signature daemons requires a heavier commitment to the top end of the resource curve.
Even so, I would suggest that the Reaction be changed to:
Reaction: When this Unit commits to a planet, put a Cultist in play at that planet.
This puts a significant delay on the resource generation, slightly mitigated by the fact that it is repeatable. It also forces a certain playstyle in order to get maximum efficiency, and most importantly, it forces interaction between the players as the opponent has an opportunity to do something about the spawning and spawned units.
As to unit name, I suggest Word Bearer Apostle .
Edited by Prepare for War