Having recently done a low level run, I’d like to offer some advice against stuff generally regarded as conventional wisdom.
Valk is actually pretty bad low level and without magic bonuses. Without extremely high effectiveness blue troops to support, she generates a pitiful amount of souls and is at best turn neutral to the thing you are trying to feed, often putting the board in a state where, even after you have taken all the extra turns, both sides are more likely to get cascades. This is excellent for you if you can use your blue troops to wipe out the enemy team on their next cast or maintain control, but no so good otherwise. Valk becomes a lot more useful if you head on over to Merlantis and unlock Azura, as this combo can be extremely overwhelming, at which point you’ll also probably want a nice scaling 4th troop that uses blue (and a hero with a weapon that doesn’t block any of them). For example - Priest’s Hammer + 5, Azura, Valk, Rowanne. But you’ll still get pitiful amounts of souls without magic bonuses from kingdoms. A way better incidental soul generators at this point would be Banshee, as she can deal rather significant damage and lead into other casts (you can replace one of the Ranger’s on your above team with her, and use her to refill Alchemist sometimes and lead back into Ranger), but her soul generation still isn’t great without magic bonuses.
Tyri, used correctly, is the best incidental resource generator in the game at low level. But don’t farm with her. Use her to set up other troops that can set her up while dealing damage. Lion Prince is a decent choice here, if she can destroy at least 11 gems they can be used to set up each other. For the last slot I use Dragonian Rogue, but you could use something like Pandaska Guard just to keep the mana and damage flowing. You could also put Tyri in with the Alchemist/Ranger combo to help set up either or both of them and get your damage out. The key here is just want to pick up maps in your normal gameplay without causing yourself additional delays or repeating content just to gain maps - tyri casts either to create cascades, fill herself and line up matches for your troops, or fill troops that cause minor generation effects that can feed each other. Most of your damage is still going to be from setting up the hero for skulls, and the board mod usually makes this pretty easy. When you have the maps, you burn through them while making moves as quickly as possible - trying to be “conservative” with maps generally leads most people to swear off the mode altogether, because individual runs tend to not give much no matter how much effort you are putting in, but you should see some significant gains across multiple runs (particularly in souls, funnily enough, making tyri a much better low level soul generator than valk). This combo also works far better with magic bonuses, which brings me to my next point…
Many people suggest to unlock all your kingdoms before you attempt leveling them and even at that point to slow-roll them all to level 5 so you can get a decent amount of passive income going through tributes. The thing is, this costs about as much gold as leveling two kingdoms all the way to level 10. Furthermore, most players tend to be pretty active with gameplay at this stage way more than they are at collecting tributes. And while these tributes do add up, I cannot stress what a gamechanger a couple extra bonus points of magic can be at his low level, particularly in allowing Tyri to set up into other troops, making her a viable incidental generator for slightly more troops, which in turn means faster battles, which in turn means you’ll be able to get through more stuff with active gameplay, which generally adds up to more than what you’d be getting for your 2-4 kingdom tributes at 0*. During my last low level run, I had Zhul’Kari to level 10 within my first three days, before even unlocking my 5th kingdom, and never regretted it - even though I collect tributes much more than an average player of this level would.
Also, if you haven’t already, settle on a hero class and level them to 20. Level 20 her with a few talents one-shots almost anything that isn’t a hero at this point with skulls and has four times the stats of most stuff you run into except the other hero. Warlord and Dragonguard are good early choices (most can be made to work, but having early massive attack bonuses is nice).
So, tl;dr:
- Recommend not using Valk at all until you at least get Azura or another strong/high scaling blue to fill out your team
- Recommend not “farming” with tyri but using her as an incidental generator and playing through maps quickly rather than carefully (unless you really, really enjoy treasure hunt)
- Recommend not “farming” souls at all at this stage of the game (you need at least +5 kingdom magic bonuses before you should consider this, and even then I’d wait). Arena, treasure hunt, and even completing challenges are far faster methods for getting some quick souls right now.
- investment in leveling your magic kingdoms to 10 ASAP (occasionally, even above unlocking other kingdoms) will see immediate returns on how effective your troops will be, particularly the above-mentioned troops, allowing you to use incidental resource generators in teams you can actually progress with rather than dropping everything to farm
EDIT: I should stress here that the way you play the game is entirely up to you. There is no “right” or “wrong” way to play here - the game can still be plenty enjoyable even if you never progress past the beginning stages. These are simply my experiences going into the game at low level while having knowledge of how the game works as a whole. I feel that avoiding getting into a “grinding pattern” early on can help the game stay fresh for longer, but some people are a lot more tolerant of this than I am. In the end, you’ll need to do what is best for you.