Afaics the paper has an important omission which is that when the disloyal generals (traitors) are not colluding (i.e. can't trust each other) then they have no reliable means to disrupt the loyal consensus.
This is a good observation, the results should differ depending on capabilities of the traitors and some traitors may compete with each other unintentionally helping the good guys.
PS: By the way, classical BGP mentions somewhere that traitors collude AFAIK.