Unless there's good evidence otherwise, Occam's Razor suggests that, as a working hypothesis, all the anthrax is from the same batch.
Based on the infections, the Boca Raton anthrax appears to have been approximately as potent and as "weaponized" as the NJ anthrax. Two people at AMI got inhalation anthrax; nobody at the sites of the NJ mailings did, although there were cases of inhalation anthrax from cross-contamination (postal workers, Nguyen, and Lundgren). [I assume that the hypothetical FL envelopes didn't go through the "squeezing machines" that the NJ envelopes went through, accounting for the cross-contamination problem in NJ only.] Also, the AMI anthrax was said to be surprisingly widely spread throughout the entire AMI building, suggesting that it had also been treated to prevent clumping.
I gather you think otherwise (that is, that there were two different batches of anthrax of different grades, or maybe three -- (1) Boca Raton, (2) New York TV networks and NY Post, (3) Sens. Daschle and Leahy).
Am I missing something in my argument that all the anthrax was of a similar grade and came from a single batch?
I am 100% sure Keri knows the answer to that.