Stranded - A Multi-Household/Rotation Survival Gameplay Challenge

I've just started this challenge and made a copy of your spreadsheet. I'm really enjoying it so far but just want to check and make sure I'm understanding it right. Once you've unlocked one of each role the only way to add more sims is having children right?

Also just FYI - on the spreadsheet the builder role doesn't unlock when you put in level 3 skill like I think it should.