What i always do is simply keep upgradeing my spearmen and focus them in a concentrated line ( just spawn in one place and enjoy the show ) hope this helps!
it really doesn't matter what race you are. it is a lot better to train your units a lot than to buy a bunch of units and don't train them much. Start by attacking the teams who are very good. (ex: the teams with the special unit, like the team with whirlers, giant trolls, and others) Basically just do the highest percentage one when it is like only 13%. You want to beat all of the other territories before you attack the demons, because they don't get better unless you beat a emon territory. It is very important to train swordsman, because they can be very good if you train them a lot. They load fast too. If you are going to buy another unit i would buy a halberier. They load very fast, they are cheap, they have good damage, long reach. they are kind of low on armour and very slow but you can train those.
i was just posting my oppinion. That is a good idea, though here is my only complaint. If they have a tough unit that they can send one of then kill like 5 of your people, they will get a charge fast.
Well seems you only hang on some spearmans, doesnt let you win always! be smart and when charge is availabe, wait for your strongest units like mounted spearman, fast strong and a high armor.