This is a rough overview of the Astartes of the 10th Host, as it was after the post-Samson Reconstitution, but before the Hazeroth Advance.

Great Crusade Heroes (<10): These are the original Marines from the 10th Host. There are extremely few left and they are all Colchisians (except Castor of course). Includes Castor, 1 elder dreadnaught, 1 chaos champion captain, 1 terminator veteran sergeant, 1 chaplain.

Long War Veterans (200): These Marines are true Veterans of the Long War. Many have been around for a very long time indeed, but some have only been Marines for a few centuries. It is not their absolute age that defines them; what sets them apart is their undeniable skill at arms and the sheer amount of combat they've seen. Equivalent to Space marine Veterans. Roughly half of them serve in the 1st Company, whereas the most of rest serve as officers, squad leaders or hold important support and staff positions (many of the latter have Terminator Honours, and could go into battle as Terminators if so desired).

10th Host Marines (700): These Marines form the bulk of the 10th. They have been around for a while; some of them for thousands of years, others for as little as a few decades. In terms of skill they are (on average) the equivalent of Corpse-God Marines. Their equipment is (generally speaking) inferior to that of their Imerpial counterparts. They are completely fearless (more or less) and extremely zealous (more so than other Astartes, including most Renegades). Their gene-seed has already been harvested.

10th Host Scouts (200): These Marine Scouts are freshly made from the (cloned) gene-seed reserves of the 10th. The candidate material was decent enough, but the creation process has been GREATLY accelerated and the gene-seed used has been forcecloned, which may lead to severe complications down the line. Doctore is overseeing the health of the new recruits, but even he cannot guarantee that all of them will remain viable (but there are more batches coming, so not all of them are required to survive - besides there is a very limited supply of Astartes wargear remaining, so it might actually be a GOOD thing that many will die). Training is inferior to Imperial Marines. Equipment is inferior to standard Scout gear. Morale and loyalty is quite high!

Castor's Veterans (50): These are the handful of Marines that have followed Castor for a while. They loyalty is uflinching. Includes his Command squad and a squad of Anointed (stationed aboard the Bringer of Faith), plus various veterans that now have places in the 10th Host TOE (mostly the 5th and 9th Companies).

Castor's Childer (100): These are the new Marines/Scouts that have been raised by Castor. From captured gene-stock (harvested Tigers Argent battle casaulties and the stasis cache - reconsecrated of course) or from a small quantity of carefully hoarded gene-seed harvested over the years from Castor's own men. These men are still quite fresh to the extent that many (most?) would still be Scouts if they were not sorely needed and the wargear was available. Alfonzo is from this group.

(numbers are approximate - i.e. there are not EXACTLY 200 Veterans)