Rainbow Marines in VI
The new sixth edition rules allow all armies to take Allies. The five Space Marine Armies are almost all Battle Brothers with each other (as per the fluff Dark Angels and Wolves are not). Since this means they treat each other as friendly units there is little reason to not take allies (points permitting). There is a slight cost since you have to take a HQ and one more troop unit from the second codex in order to unlock an extra Heavy, Elite, Troops and Fast Attack slot. The only restriction is you can not use each others Transport vehicles; thinking back about all my 5th edition games though I can hardly ever remember a game where a unit got back into a transport, let alone one that was not theirs originally. Black Templers Still having an old 4th Edtion Codex Templers have some good options with 6 man laz-plas units and Terminators with Tank Hunter. On the flip side they still have 50 point Rhino's so they are the only army that would kind of like to borrow s