Chapters a detachments question.

[West Bertozzi]

Im running my Ultramarines at an event. We have 3 detachment limit so it's hard to fit it all in for what I'd like to do. Im running Ultramarines but want to add a Ravenguard sfts unit of aggressors, maybe also sternguard. but dont want the tax of a full detachment of vanguard character and such. If I ran my ultramarines with one or two auxiliary support detachments I could use them as Ravenguard and then have access to sfts? Is there a better way im not seeing to do it? Te biggest problem is the event Im attending is cards AND killpoint diff... so trying to keep unit count down. Also secondary note if I ran a vanguard of assassins could the captain be ravenguard and give a re roll ones to the unit of aggressors? 

[9x19 Parabellum]

Ok so...

 

-all Space Marine units and models in a given detachment have to have the same chapter keyword in order to benefit from the Chapter's Chapter Tactic.

 

-you mention aggressors and sternguard.  1 more small unit (an apothecary or company chamption are each 1 model) and you can get a lieutenant for like 63 pts.  That would get you a vanguard detachment for +1 CP (instead of an auxiliary deatchment for -1 CP)

 

lastly, this question:

 

"Also secondary note if I ran a vanguard of assassins could the captain be ravenguard and give a re roll ones to the unit of aggressors? "

 

So, I think what you're asking is, if you ran a Vanguard detachment consisting of (x number of Assassins), + a Raven Guard Captain and a Raven Guard unit of Aggressors, would the captains to-hit reroll from "Rites of Battle"apply to the Aggressors?  The answer is "yes", the Captain's to-hit reroll would apply to the Aggressors, but not the Assassins. However, neither the Aggressors nor the Captain would benefit from the Raven Guard Chapter Tactic.

Edited March 15, 2018 by 9x19 Parabellum