I’ve done this about half a dozen times, the most recent time in 3.5 which I’m still playing now. Mainly, you still want high scaling stuff, and you still want damage that flows into other damage. Tyri is super important for cracking the first scarcity barrier before you get into a guild, but there are so many easy little weekly rewards you can cherry pick now that “farming” the same battles over and over again is not something I’d recommend nor is it necessary. Just use Tyri in your team as you progress though quests, and maps you get from her as quickly as possible and until you get bored of them.
I always started on Warlord class because it is the easiest to unlock. Traited or not, dragonguard is good (especially with Dragotaur) as is Titan (because Titan has ridiclously good talent options).
Some low Rarity troops to look out for:
Lion Prince: Scales with board, has board mod, good damage
Ranger: Scale with living troops, huge damage compared to early game stats
Dragonian Rogue: Scales with board, has board mod, good damage
all of the transformers: Don’t recommend using them too heavily at first, but there are some neat mini-chains (eg., Alchemist on green/brown > Banshee blue to red > Alchemist on remaining color to fill the team and reset the board > Ranger to finish off), and obviously hard loops (alchemist/hellcat/goblin rocket)
Dryad: Ridiculous early game healer
Dragotaur: scales with board, buffs for dragons, including Dragonguard hero
Pandaska Guard: Low damage, but can generate a bit of mana with it.
Knight Coronet: Amazing set of traits, scales with board, has board mod, good damage
Clockwork Sphynx: Amazing armor buffer and generator, scales with board, has board mod, really good second trait. Really, really good in Rowanne setups. Also good as a defensive buffer, and with the Razor Armor talent on hero.
Probably a bunch of others I’m forgetting.
Rowanne and Azura are among the best at what they do by a wide margin, and Tyri is unique in her support role of both mana and map generator. Lots of others are decent, but the former two can build teams around them to great effectiveness, and Tyri can fit in a wide variety of teams without stepping on too much.
Nearly every super early game team you’ll probably want to compose as
Hero(crappy weapon that doesn’t block anybody important with high attack bonus that you probably wont be casting much)
troops that deal damage with board mod, feed something that deals high damage, or set up for high damage with as few turn drops as possible, or buff enough defensive stats to stay ahead of enemy damage while trading up while also preferably not leaving you on a board where your next move can’t get you mana that leads into high damage
Which is pretty much the same strategy I use at high level, minus the hero with crappy weapon up front. Only you might, for example, be using a Lion Prince to feed a few mana into the next thing in your chain, requiring 1 or 2 mana swipes between each step, but still getting 8-14 damage out of each step, but you also might still cast Dragonian Rogue and cascade a few times, filling your Lion Prince to destroy a row and dealing a total of about 35 damage in one turn and ending with some mana on all your troops at a stage where casting your hero’s weapon is worth like 7 damage and a guaranteed turn drop.
When you get some legendaries and better hero weapons, then you can start making higher power teams and eventually stuff that lets you win three trophies reliably, then quickly and reliably.