Doubt about damage.

So guys, how are you? I want to know what to put next to the artillery to get more damage. I'm usually placing infantry, but the damage is low. Another question I have is about the number of troops placed alongside the artillery, if I leave 10 artillery with 40 infantry it will give a total of 50 troops, right? If I place 20 artillery and 100 troops, will the damage double?