You can do a few things about that:
1. Craft a bunch of Orc Nests from the Magic Academy, then deploy them.
2. Upgrade your
armories up to and past level 20. Don't forget to start Orcs production in them as though they were a manufactory.
3. Build and upgrade the Heroes' Forge Ancient Wonder.
To help improve its orc output, complete more provinces and upgrade the AW's level. Here's mine:
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Whatever you do, though,
DO NOT EXIT CHAPTER 8 WITHOUT AN ORC STOCKPILE. Once you reach chapter 9, Tournament and Spire are going to start wanting orcs, and if you're not set up for fighting, you'll be completely out of luck for however long it takes you to scrounge up enough orcs. With a stockpile, you can buy yourself some time to make adjustments to your city
before you run clean out of
dirt orcs.