But, what do you do special with a Space Marine Chapter who's only differentiated from the rest for their fanatical adherence to the Codex, and their devotion to a pure geneseed? You emphasize one of those aspects. But, how do you emphasize either of those (without resorting to FW rules)? The Ultramarines are already the epitome of the Codex chapter, not much I could do that would look any different then the boys in blue.
So, geneseed purity was my target. First answer was easy. Nothing says "this marine is pure" like purity seals! So, each of the Red Scorpions get at least one, and likely more. My second decision is a bit more subtle. If the Chapter wants to maintain their purity, what is the best way to do so? That is right, isolate themselves from contaminants. Best way to do that? Keeping their helmets on! Every model in my Red Scorpions army has their helmet on. It is something no one notices, unless they actually go looking for it. And if they do notice, its likely they assume I do it because I hate the bare heads (not true! I have no problem with bare heads, it looks dramatic!).
Of course, this does lead to the occasional headache. Metal models for example. How many Librarians in the current range have a helmet on? Thats right, none of them. I had to find one of the older range models to fill that slot. Im just grateful Sevrin Loth had his helmet sculpted on. Half the Chaplains are also bare headed, so I have limited choice on those. The plastic Commander kit was lucky for me, and I am very happy that all versions of Carab Culln have separate heads/helmets.
Of course, the question comes up: "Why not use the Forge World rules, give your squads Apothecaries?" Several reasons. First, I dont want to have to take Culln in every army. Second, that is a lot of money I would have to throw to get the bits or metal models for each Tactical Squad. Third, how many people have you started a pick-up game with would allow Forge World rules? People get antsy when I tell them I use FW shoulder pads....