I'll just say that this game used to be better than it is now. They have made some terrible changes, mostly with the AI. In skirmish mode it is so stripped down that it just runs around aimlessly and dying, and in conquest mode it is so overpowered as to be impossible on some missions in extreme difficulty. The AI basically cheats, it builds a relic and has a massive army within the first year, all without mining any iron or not possibly having the resources to build it all.
In the conquest mission "surrounded" it's 3 vs 1 against you, and within a few minutes of starting the enemy is right beside your starting tile and already attacking your territory before you have a single soldier. It's just lame honestly, there's no sense of a challenge, it's just straight up cheating AI. One set of mechanics for it, another for you, and they are not even remotely equal.
There are other conquest missions equally unbalanced in extreme mode especially, and these are the ones where you have a couple of years win it. In the "Gates of Helheim" mission you have to capture and hold 3 gates that endlessly spawn fallen valkyrie enemies, which kill your warriors in two hits. It's impossible to build up enough troops within two years to have a chance of holding one of these gates. So many other flaws I'm not even going to bother with, but these are the main ones. Another mission with the dwarves where you're swarmed by like 20 of them over and over again, in extreme mode it's impossible. 5 years to win? What a joke. I have tried countless times and even with a hero and 20 troops it can't be done. Even shield bearers are dead in 3 seconds. Again, lame.
If you like feeling like playing a game where the AI is cheating the entire time and having no immersion because of it, this is definitely the game for you! I find my time on this game frustrated and angry, and if a game does that it's not worth playing because the devs have completely missed the point of a game. The campaign is fun and definitely the only good part of this game.
Edit: The latest "Claws and Jaws" update has made things even worse, more wildlife than before surrounding your base on extreme mode, and less food tiles. It was common to find 2 or even 3, now it's only one the majority of the time. I instantly quit those missions and start again because you have zero chance with one food tile. Whilst you're still trying to not let your clan starve years into the game time, the enemy rolls through with a massive army and decimates you, you have no chance whatsoever.
Something is also wrong with food production again, in winter I had every single villager producing food, no wood, no coins, no troops, and even with the 40% less harsh winter perk, my clan was starving to death. The game mechanics are utterly broken at this point.