jailbreak

Yeah, definitely set it to No Collaboration. You can select multiple specializations - they are gained at a base rate every day, plus a multiplier (that you can upgrade through food and housing in the game) and that setting changes the base multiplier. If you're only 3 people, you'll need lots of specializations each to fill out the needs of the tech tree. Generally, the games' wiki, https://eco.gamepedia.com/ is a great resource since it explains a lot more than the ingame text.

Please no longer link to gamepedia, we stopped our cooperation with them and the wiki is no longer official nor endorsed by us or worked on by the former wiki admins. We use https://wiki.play.eco now, without ads and recent software. It also allows anyone to edit, without permanently required approval by Wiki-Admins nor with the requirement to register. Registered accounts get patrol rights automatically after a while, just like on Wikipedia.