"I've ensured that all instances of fictional team names were changed"
Clearly not else it would have changed.
If they don't appear via a search (I presume you have what you think is a table) then there is some compression, text done as graphics (should be fairly obvious if this in the tile viewer in the emulator, though if the pictures you provided are anything to go by I would be surprised -- most times graphics will be used to be fancy, not the exact same as the original font used everywhere else), different encoding (games can have multiple tables), piece of formatting preventing your search from working or encryption (unlikely for anything that is not a PC game).
I don't know what we are suggesting for tracing emulators on the megadrive these days but such things would fairly quickly reveal where it is stashed in the ROM, otherwise you get to play elimination, corruption, maybe search for smaller fragment of the name (might appear if compression or some kind of formatting/markup), or hope that a new bout of relative search finds the encoding that the screen in question is using.