1300 inf is a very small amount of troops. The max you can build at one time in one city is 2500. Let's imagine you built the most you could for a week.... From one city that would be about 17k-25k inf.
That's really not hard to do, and if you hunted 25k inf you can pull in gemstones and more commonly around $15k-20k.
Let's imagine you did this and had 4 cities.
Put your 100k inf in one spot and you'll be satisfied to know people will see your harvests and be inspired to write forum posts!
Sounds like a lot compared to 1300 inf, but it's not really.
There's a great guide to determining harvest results in the guide section. Check it out and you'll be a hunting master in no time.