Okay, here's various issues with Awakening.
I say there's more to do with what's in the game. Go more into detail on the religious conflict between Naga and Grima. Have more involvement from the playable time traveler characters who aren't Lucina. Have Validar actually show he can be taken seriously as a foe, rather than be a chump through the game.
Things were going their best in the chapters dealing with Gangrel. The game never presented it as such, but I suggest that the first difference shown or mentioned in-game between the present and Playable!Lucina's timeline is there being peace between Ylisse and Plegia. Which would also go with a character divergence for Playable!Chrom from the Chrom who was killed in Playable!Lucina's timeline, who develops into honoring his sister's ideals as much as he can rather than him going more towards righteous retribution. If the game explored more of the conflicts leading up Robin going dragon, I would be more supportive.
Valm, on the other hand, had the tension of a rising empire. If you play Walhart's recruitment and explore his supports, you'll see it also has the not really explored enough undertones of a clash of ideologies. You have peace through unification (Walhart's conquering spree), peace through extermination (the Plegian hatred of Ylisse) or peace through tolerance (Emmeryn pushing for tolerance). The chapters dealing with Walhart didn't go into enough detail of Walhart's ideology. It didn't even really deal with the enforcement of peace, or any grand destiny past Walhart's lifespan. You are not informed of Walhart wanting to stop the Grimleal until after Walhart has been killed. Valm ended up being personified more by the treacherous and conniving Excellus than by it's actual ruler.
The chapters dealing with the Grimleal after Walhart is killed are disappointing. They're more into being Chrom and Robin's personal journey to prevent the future Playable!Lucina came from than the exploration of the implications or developments leading to Grima!Robin going dragon. A few maybe good points to cover were a letdown in execution, such as the Avatar's parentage, the Avatar's role in the alternate timeline and what led him going dragon, Validar, and Grima himself. Validar and Grima are lacking when it comes to backstory and motivation about them. They're warring on mankind because.....?
Really, why does the Grima, a god among so many many mortals, bother with the wipe out mankind thing? What future does she want to bring, that he prefers to the present? The same goes for Validar. He isn't the Avatar. As far as I can tell, he's lunch. He doesn't even have a plan to get rid of Grima once the time came like Gharnef did when he was helping out Medeus, which would be an improvement. This is a problem with the Grimleal as a whole, as none of the named enemy Grimleal members who appear in more than one chapter really have enough when it comes to motivation and backstory. What's in it for them? It's not power, the favor of Grima, revenge on their enemies, or even a chance to be spared. They aren't like the Loptyrians who were favored by Loptyr.
Various other posts on this blog will go into rewriting Awakening.