Awakening characters being vanilla? Dude, yea, I disagree with that. In other Fire Emblem games there's a bunch of characters that barely have personality and appear mid-game or at points in which your little group is already familiar and awesome.
In awakening it's literally difficult to not want to include new characters into the fighting party. The personality quirks are hilarious and the support conversations are actually easily accessible. The only other FE game where I liked so much of the cast was Rekka No Ken, while other Fire Emblem games sold me on about five characters each and the rest fell into the realms of the forgotten.
Granted, the small group of PoR characters I care about are a very awesome group. Nephenee, Soren, Mia, Lethe ... truly awesome characters. Same with Sacred Stones: Joshua is hands down the best swordmaster ever.
Don't think this entire post is for you, so much as whenever I talk about Awakening and I don't keep myself in check, I have a lot to get out of my system.
Fire Emblem loyalist would be upset from going to Awakening after the Tellius games because the Tellius games have far and wide the best writing and the best cast of characters we have ever seen. They are as quirky as they are believable. Awakening's cast has flavour, but they're scarcely human.
Awakening seems to do everything in its power to take away suspension in belief. Fantasy of all things is supposed to enchant viewers by adding a touch of the impossible to reality, often with historical references and inspirations. That said, this does not apply to plot happenstance or character development, for very good reasons. it is harder for the reader (or player) to form bonds with characters who don't really seem like they have any world outside of filling a specific niche that you would pull straight out of an anime.
Chapter 4, where they arrive in Ferox, is where the player typically stops caring.
Oh, you just killed my entire border guard? Awesome skills, lad! Don't worry, their families won't care.
So get this: I can't help you with your war. It's because I am not the ruler of this domain. BUT YOU'RE IN LUCK! A tournament is going on RIGHT NOW, where we select foreigners to fight for us (THIS MEANS YOU) to determine who runs this joint. IF YOU WIN WE CAN SEND SOLDIERS RIGHT NOW.
Yeah. There goes all my interest in the plot. The Tellius games never did ANYTHING that ridiculous. To go back to the characters specifically, like the rest of Awakening, the characters are all quantity and no quality. How is it that the children, all barring Lucina are entirely optional, have more interesting backstories than almost everyone else? How is it that characters like Virion are the oddballs to actually have any depth to them? How much better could the game be if we had someone like Brady in the main cast, to actually have reasonable assessments for a given situation?
Compare it to Path of Radiance. Ike, Soren, and Titania can all have such drastically different reactions to something, but they all have different ideas of how to respond. Mix in someone like Mist or Shinon, and things get even more dirty. Yet, we all know about Shinons, Sorens, Titanias, Mists, Greils in our life. That didn't stop them from making the characters interesting.
I rather have had them cut the Awakening character list by 10 and focus on making the existing pool of characters better. As far as gameplay is concerned, if you don't make second seals so ridiculous inaccessible for the first 16 chapters of the game and penalize people for class changing, at least people would still be able to have the team composition their want. ALL characters need at minimum a segment before and after the chapter they appear in for proper development. After that, don't pull off a Kellam and have him reinforce his stupid trope every time he talks. That character was at his best when he is talking to someone like Donnel or Nowi and we get to actually know more about him.