Grom's starting position is brutal. My first try had me constantly fending off invasions from Yvresse, Saphery and Eataine. When Yvresse then allied with both Mousillon (who I'd left alone) and Clan Skryre, it was game over. I lasted about 15 turns before I threw in the towel.
The second is going better. I'm sitting on a mountain of gold, and I've just invaded Ulthuan.
I've failed my Grom campaign 3 times now lol.
I think it's the economy that is killing me. Any tips for economy and army composition?
Are you conquering?
Grom has a problem. He's surrounded by enemies. His economy is poor. Early on, you'll struggle to afford enough armies to both defend your territory and conquer new regions.
The solution is simple. Don't conquer. Raid and pillage Brettonia to build up wealth. Sack any settlements you take. And use the funds to build up Massif Orcal. You need to recover quickly and move on to the next fight, to keep building up your cash reserves. So grab replenishment buffs at the earliest opportunity.
As for army composition, you're the Goblin King. Your armies should be mainly Goblins,wwith a focus on buffing them through research and recipes.