If you had to remove characters from FE6...

[Frickomode]

Merlinus. He's such an unnecessary waste of code and dialogue that could have gone to someone who Roy would actually defer his plans to for advice like Marcus. Or someone Roy would enjoy the company of, like Llina.

[ping]

I'm generally agreeing with the position that BinBla's cast has surprisingly few "unnecessary" characters that don't stand out one way or the other, but if 10 characters had to go...
(in order of their recruitment)

• Bors. Barth is funny in his knighty knightiness, Wendy is unique in her terribleness, Bors is just kinda there.
• Treck, as much as it pains me. But as a bunch o' numbers, he and Noah are a double back-up for a class that already has its fair share of characters. And between the two, Noah with his higher base level and sword rank is a better potential replacement for a x-mas cavalier.
• Ogier. He and Fir are pretty similar in their roles - low-level sword user to train up during the Western Isles - but Fir (at least on HM) is just better than him. I never really used him because of that.
• Geese. I know, I know, only pirate and all that. But like Ogier, he gets overshadowed by a character in a similar-but-not-identical class who joins at/around the same time - in his case Gonzales.
• Elphin or Lalum. Unlike Echidna and Bartre, they're basically the same unit with different support partners. It would hardly change anything (in terms of gameplay) if one of them would join in both routes. Although I guess random/reversed recruitment players would be devestated.
• Dayan and Yuno. Mostly because Yuno doesn't really have a role except "air taxi for ch.21" and then applied symmetry to get rid of Dayan, who does have some combat (and rescue) utility in him.

Aaaand that's only seven. Er... I guess Igrene (somewhat similar to Klein), Douglas (very underwhelming, but neither hilariously bad like Wendy and Sophia nor a fun growth project), and Yodel (discount Niime, but that's still fairly good)?