I don't think there's anything in the five niyamas that suggests collective kamma in any way.
It's interesting to note that when Peter says there are incidents of the "a group of people committed an act together and at some later date suffer the result together" type in the scriptures, this is correct... but generally speaking tales these aren't in the actual suttas, they are in the Jatakas and the Stories from the Commentaries. Whether one chooses to give credence to them depends on how authorative one considers such legends to be.
Generally speaking such incidents would require some kind of 'alignment of cosmic factors' or other mysterious forces of coercion and influence to contrive such results. Bringing the intricate web of causal events in such a way as to fabricate a scenario such that kamma can poetically come to fruit is not the kind of kamma that the Buddha taught about. He taught about a direct relationship between wholesome and unwholesome mindstates and the discernible results of those volitional actions. He also taught about transcending the ups and downs of kamma and vipaka through wisdom, and seeing things as they really are.
"Do not force others, including children, by any means whatsoever, to adopt your views, whether by authority, threat, money, propaganda, or even education." - Ven. Thich Nhat Hanh
"The uprooting of identity is seen by the noble ones as pleasurable; but this contradicts what the whole world sees." (Snp 3.12)
"To argue with a person who has renounced the use of reason is like administering medicine to the dead" - Thomas Paine