I am up for this game, having enjoyed Loren The Amazon Princess.
What I’d caution is that the reason people love the “wild escapist power fantasies” is basically because when the MC is that powerful their choices matter by default. But that’s separate from power; it’s generally called agency.
Samwise Gamgee is no one special from a power perspective, but he has agency. He is an ordinary person, but the theme of his story is that you don’t need to be special to do something important. Remember, Sam directly saved Middle Earth. Frodo was carrying the Ring to Mount Doom, was captured, and lost the Ring. Sam picked up the Ring, rescued Frodo, and gave it back so Frodo could carry it to Mount Doom. And that’s why Samwise is a viewpoint character and all the great princes and kings and honorable warriors who die in the Siege Of Gondor aren’t; they’re Aragon’s supporting cast.
But you could make a story out of any of the little bits mentioned in the description of the Siege Of Gondor, it’s just that it’d be limited in scope to leading a unit of Riders Of Rohan from the opening charge through battling the Easterlings and Haradrim and keeping your men (optionally including Shieldmaidens of Rohan; it is implied Eowyn is not the only one) from being on the recieving end of a Nazgul airstrike until Eowyn and Merry can kill the Witch King. I’d also play that game; it’s akin to Chronicles Of The Black Company, where the protagonists (note: not heroes) are a mercenary company in service to The Lady and they spend their time fighting rebels and trying not to get caught in the middle of feuds between her powerful wizard councilors The Ten Who Were Taken. Over the course of the initial series they end up being involved in the presumed deaths of most of the Taken, but usually another Taken or one of the rebel’s powerful wizard generals significantly assist, because the reason I say presumed deaths is that it’s a known fact in the setting that wizards on the level of The Taken do not die when you kill them. It’s also a massive inspiration for the old Bungie Myth games, where the protagonists are a military unit aiding the mighty wizard Alaric in defending agains the ancient evil wizard Balor and his dread generals Soulblighter, Shiver, and the Deciever. So when Shiver dies it’s just narrated as “Alaric defeated Shiver in a spectacular Dream Duel” because this isn’t a story about Alaric killing Shiver.
Also technically the main character of Chronicles Of The Black Company isn’t even the commander of the Black Company, but that’s because the framing device is that he’s the Annalist and it’s his job to maintain and add to the Black Company’s historical account and tradition requires him to read a selection from them to the men every night when practical. So pretty early in each story you get “In those days the Company was in service to the Syndics of Beryl…” or “In those days the Company was in service to The Lady of Charm(that’s the name of her wizard tower)”. For a Choicescript game I’d think it’d be better to play the Captain; the Annalist has moderate agency but is often on the recieving end of “Captain’s orders.”