I think a big sin of MGS 4 (among its many others) was not bringing back Natasha Romanenko. Obviously, Naomi was an important character, considering her involvement with FOXDIE, but Natasha was the one who helped expose the Shadow Moses incident to the wider public through the book In the Darkness of Shadow Moses, after which she went into hiding. She would've been a perfect addition to the cast alongside Raiden and Rosemary as people hiding from the Patriots now desperately trying to keep an increasingly unraveling situation under their control, potentially providing support to Snake and Otacon in their global activities. The only reason she likely didn't come back is because most people didn't really interact with her that much during MGS 1, compared to Naomi and Mei Ling, so was unable to have as much of a nostalgic well to pull from. As someone who dedicated herself to anti-nuclear activities, how would she have reacted to the emergence of the war economy and its implicit justification of eliminating nuclear superpowers and resulting near-catastrophes?
As an aside, I just love the fact that In the Darkness of Shadow Moses is, in fact, an actual novella that they wrote up and included in the menu options for MGS 2. You can actually read the damn thing, as well as the account of the conspiracy theorist and peanut butter-averted journalist Gary McGolden contacted to leak it (yes, even the most minor of side characters has that signature Metal Gear weirdness).
