I did it with knights, mages, and grenadiers. Put your shields into income, food, and unit damage and defense. Use the high damage spells on the ranged enemies and the interrupting spells on the melee enemies.
I highly doubt you cleared that with just riflemen even on easy mode. My method works up to medium. On hard you pretty much have to have the premium units especially the knight cavalry.
sure did lvl 3 food/resource at max,physical dmg at max,hp/armore at max,only 1st upgrade in tower,nothing in mgic, i had 91 sheilds.
up speed ,you start most boards being able to make 21-24 riflemen to start.all you do is keep making them and collecting gold. you can also do this with knights as well
huh you're right I just beat it with only riflemen on easy. You take a lot of losses but you have pretty much a constant stream of riflemen. When the hero comes out I just used war cry and it gets killed pretty fast.