Join Date: Aug 2009
Location: Portland, Oregon
A lot...possibly thousands of White Scars were swung in the favor of Horus.
There's on traitor Raven Guard that fought for the Night Lords.
Roughly two butt-tons of Dark Angels fell under Luther's sway.
And it depends on where you cut the Alpha Legion. They're a mysterious box of chocolates.
That's off the top of my head.