Actually, I think Ike/Soren is the kind of pairing it's good to have a ship manifesto, because it's the sort of thing someone might not get and wonder why so many other people do, which as far as I can tell is the only useful purpose of ship manifestos (apart from letting people write extensive meta about their OTPs). Pelleas/Micaiah could possibly work that way too, though it's not as common in the fandom.

I'd be tempted to try a FE manifesto, but I lack the fandom credentials.