[quote=@BCTheEntity]
[@Jbcool] Something that I've just read up on that bears mentioning, but the prime figure in a Genestealer Cult is not the Broodlord, but the [url=http://wh40k.lexicanum.com/wiki/Genestealer_Patriarch]Patri[/url][url=https://1d4chan.org/wiki/Genestealer_Patriarch]arch,[/url] though as of 2016 revisions they are physically similar. Broodlords are kind of just "souped-up Genestealer sergeants" in terms of role, unless they're Vectori-strain, which I wouldn't have immediately assumed myself due to those being somewhat bizarre in nature. Just a thought.
[/quote]

The main difference between a brood lord and a patriarch is that a brood lord begins life as a brood lord, where a patriarch is originally just a genestealer, that has grown more powerful to fulfill the role of leader of the cult it's created. Functionally, they are the same basic creature. So much so, in fact, that if a cult ever encounters a full-fledged hive fleet, the patriarch is treated as nothing more than your average, run of the mill brood lord. This is reinforced by their stat-lines being virtually identical in the game.