I wanted to put up 3 pics here so I can talk about something that everyone in the Pre-Heresy community can take advantage of; a little pre-planning.
From the outset, I wanted my army to be usable as both Loyalists and Traitors, and not have to start over from scratch and paint 2 entirely different armies. So I did a little preplanning. Nothing major, just an hour of so going through all the possible bits and minis GW offers in both the CSM and Imperial SM ranges (dont forget about the Collector’s Range as there is quite a bit of good stuff in there for a Pre-Heresy hobbyist to enjoy)
I decided right off after looking at the pre-heresy paint scheme in the Death Guard Index Astartes article, that my loyalist would be filthy. These aren’t dandies like the Emperor’s Children or the Imperial Fists, but battle hardened troops used to being in the field. So, they got a decent dirty brown wash that I didn’t clean up too much to give them that weathered look I was going for.
You can see the results in the top pic (a purely Loyalist Imperial squad)
When it came time to do the Traitors, I decided on ONE quick change, Imperial Backpacks. Thats it. I went ahead and threw in a Imperial shoulderpad or bolter here and there, but overall the only “big thing” I did was swap out the backpacks. When painting them, I went slightly heavier on the dirty brown wash, but used the same technique.
You can see the results in the middle pic (a purely Plague Marine Traitor squad)
Now the test. What my preplanning did was allow me to mix and match freely when I play using the CSM codex. While at a very close distance some individual models might draw attention to themselves, You can generally get away with mixed squads, and from over 1 foot, you would never know that they were from 2 different ranges.
You can see the results in the bottom pic (a mixed Imperial/Plague Marine squad)
Its not hard, and you can do it with almost any of the legions. So go out there and have some fun!