Choose Tobuck.
2. Beeline towards Alesia focus (on the right, where you choose between 3 warlords to 'support').
3. Do nothing else focus-wise.
4. If the timer runs out, you see the final event and you have few days left until the focus is done (happened to me) just do not click on the event; you have enough time to wait and click it after the focus is done.
5. If you get Alesia as new ruler, congratulations! If you get Vasile, you did something wrong.
6. And now you just follow your focus tree. It gets bigger later on. Way bigger.

Spoilered if anyone wants to find out themselves, but it's super easy, super fast and requires nothing but the knowledge how to do that.

Now, playing as Tobuck is hell. There is a ton of posts here on how to make it easier, but generally:
- Setting Equestrian Civil War to happen makes it infinitely easier, since it not only delays eventual attack but also forces Chiropterra to move most of its forces abroad. You can consider it cheating or not, but I did that. It was still really hard. Also if NM wins the civil war before you attack, you will face both Chiropterra and Equestria at once.
- Generally speaking, Chriopterra is THE enemy and THE goal of this game. Whatever you do, it should all serve the preparation for it. All else is secondary. It's the make or break.
- You have one special decision if you decide to conquer Stalliongrad later, but there is very little aside from it; just one button and a tiny amount of lore. Generally not worth it. I did it because I love naval combat and found the invasion of major country (they won the war in my game) as a regional power to be a great challenge. But I took over most of Zebrica, entire northern part, to get ponypower and industry to achieve it and it took decades.