Thanks for Playing, and yes I need to update the tutorial a bit, and I was planning to add an arrow pointing at the lone land but I got overwhelmed
you get population when you have a bigger army in the fight for example
if you have 20 and they have 10 you'll get 10+ pop as an army
if you have 50 and they have 20 you'll get 30+ pop as an army
so you have to get your army as bigger as you can so you could raise the pop