1. Made a Legion warrior, still organized with Legion (or smaller chunk of Legion, like a former "Company")
2. Made a Legion warrior, maintained Legion philosophy and markings, but organized in a modern Warband
3. Made a Legion warrior, shed Legion image and completely became part of a Warband or large pirate fleet like the Red Corsairs
4. Made a post Heresy Imperial, became a traitor
5. Made into a traitor Warband with stolen geneseed
I'd tweak this slightly and concentrate upon the origins of renegades. As I see it, marine renegades by M41 are likely to fall into one of the following categories:-
(1) A Marine of a former First Founding Traitor Legion who turned to chaos at the time of the Horus Heresy, and who has continued to fight against the Imperium for 10,000 years. (This is your "Classic" Chaos marine - Kharn the Betrayer, Lucius the Eternal etc etc) (this is your categories 1-3, Dryad.)
(2) A Marine of a former First Founding Loyalist Legion who turned to chaos at the time of the Horus Heresy, and who has continued to fight against the Imperium for 10,000 years. (This is a theoretical category. I'm not aware of any marines who fall into this category, but arguably the Dark Angel renegades do.)
(3) A Marine who was recruited as a normal human Post-Heresy by a Traitor Legion, Chapter or warband, implanted with their own geneseed, turned into a full marine and indoctrinated into the traditions and culture of that group. (The Alpha Legion in particular are said to recruit on a regular basis, but presumably others do as well to some extent.)
(3) (a) A subcategory of the above would be a marine who has been recruited into a Legion/Chapter/Warband and implanted with geneseed from another First Founding Legion. The Astral Claws in particular do this, just to keep their numbers up. (This is your category 5, Dryad.)
(4) A former Imperial Marine, a member of a Post-Heresy Chapter, whose entire Chapter has turned wholeheartedly to Chaos (Like the Astral Claws)
(5) A former Imperial Marine, a member of of a Post Heresy Chapter, has turned to chaos either on his own or as part of a small group of renegaes from his otherwise loyal Chapter (Like that handful of Space Wolves who turned on their colleagues to join Huron Blackheart's renegades)
By moving away from how the Marine operates and just concentrating on his origins, you can then remove some of the hundreds of options you talk about, Dryad.
As to the original OP's question, it's hard to say what the proportions are, really. The overall feel one gets is that my category 1 Traitor Marines substantially outnumber the other categories among chaos forces. Personally, I'd like to see more exploration of categories 3-5, as there's not a lot of information about them.
I particularly think that category 3 needs some exploration. The "classic," category 1 chaos space marine has always seemed a little implausible in some ways to me. I know that time runs differently in the warp etc etc, but the impression one gets is that the chaos marines have been fighting pretty much continuously, without break, for damn near 10,000 years. It seems to me that for there to still be huge numbers of the original traitors left, this really means that these marines dying and then being resurrected over and over again by the chaos powers. In many ways its a nice conceit, but is it really workable? Yes within the Eye of Terror, where the laws of reality break down...but in real space? If a chaos marine is killed on Ultramar, does he really "respawn" back in the Eye of Terror?
I prefer the concept of the category 1 marines forming an "officer class" of ancient, depraved and deadly warriors who lead chaos marine armies consisting of largely of category 3 marines. For this to work, the major marine warbands and Legions within the Eye of Terror would be recruiting on a regular basis, from slave or vassal worlds. (This is my take on it, bear in mind, there's not a lot of talk about these category 3 marines in the canon.)