Wow that's funny I did the exact same thing! I was working at a web/mobile gaming company building a sports draft platform and I was tasked with building a bot player to fill in empty player slots. I used a GA and it worked really well even though I didn't know anything about sports.
Funnily enough I did a similar thing - I was given a list of players with a "point score" and a "price", and I had to choose the best team I could get. One goal-keeper from a set of N, a couple of forwards, a couple of defenders, etc.
The solution my program "evolved" was the best in the company.
The knapsack problem(2), of which fantasy team picking is an example, is a classic use case for genetic algorithms.
1) https://github.com/chrxr/ga-prem-team/blob/master/scripts/ga... 2) https://en.wikipedia.org/wiki/Knapsack_problem