I think Chrom would offer more than just being Awakening incarnate, personally. A weapon-switch stance system is honestly something I can see Sakurai doing, and it fits the series extremely well.
Notably, the five newcomers received thus far "play like their games."
- Villager uses random items that he may pick up in town.
- Wii Fit Trainer does yoga.
- Mega Man has the Robot Master abilities.
- Rosalina plays similar to Galaxy as a whole, using her wand as the remote, sort of, as well as the Luma as the co-op Luma was used in Galaxy 2.
- Little Mac playing, well, true to his boxing roots, and having a power meter similar to Super Punch-Out!!
With this in mind, I feel that seeing Chrom "play like Fire Emblem" through representing the tactical aspect of weapon choice is a good way to go. Plus, we don't have a true stance character to speak of, at the moment.