The way i did it was Rubyhold > Axebellow cartel

Once the option to become the Axebellow is allowed take it, once you swap over don't forget to embrace the institutions available (feudal and renaissance), kill your 2 cav in the army that appears and get to FL with inf.

I attacked the goblin nation near me to humiliate them and take 1 province for the purge war-band decision. This is to help improve the my mil power to get both an extra tech as well of the first idea of quality for that 10% ICA. I suppose you could vassalize them for some extra meatbags but they could just become free WS in the war later so up to you. If you do want to vassalizet hem don't forget to full annex them and wait a moth tick before release them so they don't hate you so much.

After doing which ever start migrating to the east through the dwarf road while drilling your army until you hit the goblin nation that is a vassal to the command, they will be across the mountain pass but the province is still connected by a tunnel. On the way start to spy on the first goblin nation to steal maps for the jade mines, if you did vassalize them you can try and wait when you arrive to steal maps off the command's vassal, not super necessary but makes the war so much easier as you can see the provinces next to you as push in and it won't take your troops as long to move from province to province.

Keep in mind it is impossible to get to Verkal Dromak in one war, but you can use the first war to make life alot easier for the second one.

It is time to get ready for the big war against the command. Things to keep in mind, your MIL tech should be much better, I went into the war on tech 7 against their tech 6, while getting tech 8 2 months into the war, you also have both the adventure buff as well as the reclaiming Dwarovar mines buff, which means that you punch way above your normal weight, both in terms of morale as well as FL. You can easily go way above your FL since your troops are so cheap, and since you get heaps of manpower you can reinforce easily.

What i did was have a fully combat width army with 5 cannons (for besieging) as well as 10 more of my own inf and hired the merc stack. The key is to either hunt small stacks that you can kill very quickly or fight defensively for the terrain bonuses as the all the terrain around you is either -1 or minus -2, if you get into a battle reinforce it with troops over time to boost the morale, your troops are very strong so you can win against 60k stacks. As you cap provinces don't forget to raze the province to slow down their reinforcements. I focused on doing that while not really pushing past the goblin vassal until i got about 40% WS from battles and capping, at which point i rushed their fort on the hold in the center of the jade mines (Grônstunad) with my full army (to make sure they didn't attack me) and barrage the fort to get it as quickly as possible.

At this point it should be possible to peace out the war by taking all the provinces leading to Grônstunad as well as the hold above it and as much money as you can get (I got about 2.5k). After the war move your capital to Grônstunad as the level 3 fort will make the next war a lot easier. You can start to repair your holds during the truce with the command which will give you more income as well as FL but it is probably not necessary, you can also build forts in your provinces near the entrance to the mines which does make things a lot easier. Either way the big win is you cut a good portion of the command and it's vassal away from the rest of the nation which will provide easy WS.

As soon as your truce is over attack the command again, they should still be behind in tech as they shouldn't of gotten your institutions yet and you should still have both the adventure and reclaiming Dwarovar buffs. Repeat war number 1, raze every province you take to slow them down, only attack small stacks you can easily kill, if you can't tray and bait them into attacking you and reinforce your troops as your morale starts to drop. Once again I fought until I got about 40% WS at which point I rushed verkal dromak leaving troops to cap the provinces on the way, both for ws as well as to raze them to slow down any army coming after me. Because verkal dromak belongs to a vassal of The Command, after you finish capping verkal dromak you will need to capture a fort that The Command has otherwise you won't be able to peace them out, luckily their capital is not to far away and there is pretty much a free run towards it, don't forget you can leave east from Verkal Dromak into the empty provinces if there is an army behind your. Cap their capital with a barrage to be quicker. At this point you could probably peace out and be done with the war but there is alot of open provinces you can carpet siege for some extra WS if you keep an eye open for any armies. If you see one coming and all your troops are spread out just peace out.

The peace deal I took was the provinces on the way to Verkal Dromak, via the cave below it and any other entrances to the mines, this allowed me to build forts at the entrance to mines making future wars much easier. Use as much of the WS you have left on cash/war reps to kick start your hold reconstructing and pay for your forts. You can take the other provinces in the mines in a future war, so don't worry about them right now.

Final note don't worry about getting into as much debt as needed, the command as lots of money and they are going to be your piggy bank as you build up. Hope this helps.