Either everyone needs to get royalties or nobody does.

Pay your voice actors right the first time instead of paying them shit per line. Or if your video game becomes an astounding success, all 1,000 people get a slice of that 100,000,000 million it made in sales via residuals. A cool $100,000 for everyone!

Don't forget to advocate for yourself even if you have a union. Nobody ever gets paid more by saying nothing.