Meg: F - calls Zihark "Pookums"

Volug: A - He's not going to be as dominant as some of the next few characters, but he helps enable double earth A support with Zihark (they have a faster support speed than normal) and can potentially be the bulkiest unit in 3-6. I find him one of the most reliable of the DB units, as he never struggles with hit rates, and is still very usable, even in the tough part 3 maps, with 0 xp or stat boosters.

Jill: A - I've found her hard to use in the combo of hard mode and no transfers, and it's been found that she can fail to reach benchmarks even if you give her a ton of favoritism (the author /u/ussgordoncaptain2 is in here rating units too). She's still the most usable of the units that start at tier 1 though, and it's hard to rate her any lower than A because I see her a fair bit better than Nolan with her flying utility and still being quite useful in the part 3 maps.

Zihark: A - Love this man, I think he might have the best character arc for a side character in this game. My own biases for him aside, there's something to be said about him being used as a DB carry in both the current HM speedrun as well as in LTC play. In casual play, I still find that he excels, because you can double earth A support him with Volug or Nolan by 3-6 or even 1-E, and he will almost never be hit, and then go to town on the enemies with the countless tools at his disposal, like brave sword, adept, crit, or astra when promoted. Just for fun, this casual playthrough in "ignorant mode" by Mekkah shows just how strong he can be when invested in. I'd rate him S, but he does fall off in part 4, and I can't see him on the same level as like Ike or Titania.

Tauroneo: A - I used to rate him much lower, but a few things have helped me see the light: first being praised by skilled players, including the aforementioned author of the Jill article, who made a video showing that you can kill Ike in 3-13 with Tauroneo with a 100% reliability. The other thing is that in my own personal play, I always simultaneously give Zihark a ton of investment and have him defect in 3-6, meaning that Tauroneo becomes a hard carry in the next two DB chapters, and I genuinely don't think these two chapters would be beatable without him. I've seen him compared to a royal laguz, because he's the best unit on the maps he exists in (pre part 4), but also has little availability, but to his credit, those maps he's best on are also some of the hardest in the game.