@dredmorbius @bgcarlisle I don't know what H and A mean here.

Also, this is pretty interesting: https://www.etymonline.com/word/monger The verb is younger than the noun and that's why it's "monger" as well and not "mong". But the -er really is the agentive suffix , so expecting "mong" is silly sounding but also right in it's own way. Which I find delightful.