First of all pull up your pdf copy of the Blood Angels codex. Now flip to the troops section. See how there are Assault Squads there? Yeah, so if they are following standard codex battle company setup, it shouldn't be that way right?
Standard Battle Company:
6 x Tactical Squads
2 x Assault Squads
2 x Devastator Squads
2 x Devastator Squads
Blood Angels either do or don't follow that setup. I'd like to think it is actually the following:
My proposed Blood Angels Battle Company:
4 x Tactical Squads
4 x Assault Squads
2 x Devastator Squads
This also covers the idea that assault marines are the ones advanced to bike and land speeder specialists in the blood angels. If that is the only group making the grade, then you need a larger pool to draw from.
Another aspect of the fluff to cover is the Death Company. This is by no means a standard orginization. The thing that makes it really confusing is that they are formed ad-hoc action to action and rarely is there a standing formation of Death Company that travels with a Blood Angel contigent from system to system. So this means there is no standing company, but rather the company is an "Honour" roll of marines who have succummed to the Black Rage. Those with the Red Thirst to the extreme I would imagine are inducted into the Death Company but rather than being removed from their company, they continue to serve in it with whatever death company is attached untill they are too far gone and must be retired to the Tower of the Lost on Baal.
Another aspect is the scouts. These guys are veterans. And Close Combat vets as well. This further justifies my suggested alternative orginization as assault squads make a great basis for recruitment as well as the fact that scout bikers would have to be drawn from bikers who are in turn drawn from assault squads.
One last point is the Honour Guard. These can be Jump Pack equipped. Where would that come from? Assault Marines. Need I say more.
I would say though that the 5-7 companies probably look like standard battle companies and that 8 is all assault and that 9 is all devastator marines. 10 is obviously the scout company still.