Magefa- that it has been mistranslated and REALLY means RIOT.
root of word related to contact *between* people, (gff emplies embrace for example) , as opposed to the plagues in Egypt which were based on word makah.. a strike.. which can come from God. Magefa by contrast is people hurting each other in highly emotional riot situation.
(How did they have weapons? Must have been copper based... bronze or similar alloy, likely fashioned from the celim they got from Egypt, we see in Numbers the men were clearly armed for battle and fought Amalekites and others later)
Every situation I've noticed you see a *magefah* is emotionally charged situation.. the people assembling against Moshe, strong complaints, outrage.
(after Korach incident, after egel hazahav executions) .. mob mentality. never mind that 'too high a madrega'' stuff.. bear in mind human nature, complaints, numbers, situation, 50th gate of tumah etc etc.. even given losses before Exodus these are still people, let's not get unrealistic but notice how they were complaining.
Logical situation for riot in human history and note there IS no other word for such a situation in the Torah AND that magefah as divine plague is less logical explanation, unnecessary. Occam's razor. Also seems to happen within hours in the narrative, not within days which would be needed for incubation and spread of even the most virulent diseases.
'Anger from God'.. yes, God resides immanently IN consciousness of Am Israel.. much of the anger itself was righteous and came from good place but manifested violently and with deadly results.