You are free to express your opinions You are just also free to suck upon a Bloodletters raging slong
Well, I have successfully bound a Bloodthirster to a jar of (dill, not that sweet bullshit) pickles. Scientific achievement at its finest.
It depends on a lot of things. Can they infect Space Marines? Certain individuals (such as Sgt. Avery Johnson) were immune to the infection. How large is the Flood force currently? Do you mean ALL the space marines, from every chapter? Including KAOS spehs marines? What form do these Flood take? If they're Flood infected Forerunners, I'd say they definitely could.