How do normal people do it?

Characters talk about how Primals are summoned pretty regularly, and are summarily put down by... somebody. But seeing as how they can just insta-win any fight by converting their opponents into slavish cultists, how does anybody without the Echo defeat a Primal? For that matter, how did the Titan Slayers do it? They never (afaik) mention that any of them have the big E, so does Titan just not bother converting?

In the story you (apparently) always face the Primals alone, though in-game you have a party of 4 (8 in HM) that just appear/disappear between cutscenes. Do these people actually exist? Is it supposed to be possible for a single adventurer to slay a Primal?

Also, I assume in Lore the Primals actually leave their summoning circles from time to time to wreak some havoc on Eorzea, though this never happens in-game.

I'm just curious about any Lore that explains how the Primal threat is managed in FFXIV, as I intend to use them in a fanfic.

Thanks in advance for any responses!