How do?
Just a quick pondering from yours truly.
Nowadays we have 7th Edition 40k where absolutely anything goes, and we also have Forgeworld's Horus Heresy series.
Both use precisely the same ruleset, but there's a general opinion that the Heresy lists might not be suitable for general 40k play, mostly because the Marines in it can do horrible, horrible things (like 20 Tactical Marines rapid firing with their Bolters, twice in a turn. Say goodbye to your Horde!)
And you know, fair enough.
But, what exactly is stopping a player, in organised permissive play from utilising the odder, more Legion specific units?
Use your chosen armies core book (Marines, Chaos Marines, Space Woof etc), and then add in a unit or two from the Heresy unique to their parent legion.
Why wouldn't you do that? I mean the models are pretty much universally cool, and the background for them equally cool. Take my favourite unit, stylistically speaking, [url=http://www.forgeworld.co.uk/The_Horus_Heresy/Legiones_Astartes/World_Eaters/WORLD_EATERS_LEGION_RED_BUTCHERS.html]Red Butchers[/url]. What is not to like about those models and the units background? 'I'm sorry, but you're far too loony a loony. We'll just have to seal you into your armour, and only let you out when it's time to break face'.
Anyone do this? Anyone tried this? Anyone dead against this?