Y'know, the more I think about it he more I wonder what "a typical JRPG" means. Recently there was that whole "JRPGS better that FF7" list that I couldn't help but disapprove of due to its severely narrow scope. I rattle off DOZENS of other titles or series that deserved mention. Sure, Yahtzee says a typical JRPG is about "15 year olds defeating Satan with the power of friendship"...but wouldn't that make Earthbound the typical JRPG due to its arc with only its aesthetics really differentiating it? If anything I noticed JRPGs lean towards late teens, early twenties with the protagonists, that time where they're not old enough to be adults, but also not young enough to be children. Sure, the "fighting Satan" argument is realistic, but that's not exactly something out of play in fiction in general.
Recently I actually took a swing at Saga Frontier 2, a quirky game for the PS1 that has dual storylines. In one you play the exiled prince of a kingdom and live his life from literally the day he is born to the day he dies and witness the political influence of his actions. The second is about a family starting with the first generation and then ending with his granddaughter decades later. And that's before you get into its funky battle system. Can't exactly say that's "typical" with the JRPG formula people claim exists. Even with FFVII that can't work because there is ONE teenager in the entire party (Yuffie) while everyone else ranges from early twenties to well into their fifties or sixties (Vincent). And then there's Sephiroth who ISN'T Satan, but just a man who just so happens to swiftly begin attaining godhood, making him more similar to Kefka than a load of the other villains in the series.
As such, I can't really say JRPGs follow an exact template. There's just too much variation, whether it be stuff like Tactics Ogre, Front Mission, Breath of Fire, Soublazer, Illusion of Gaia, Brave Fencer Musashi, Secret of Mana, Secret of Evermore, Rune Factory, Odin Sphere, Muramasa: The Demon Blade, Persona, Shin Megami Tensei, Fire Emblem, Shining Force, Phantasy Star, dear god I could go on with this.