The founding team, like any business partnership is like a marriage. Both are social-economic institutions. Both need chemistry to succeed. Both are really mess

The founding team, like any business partnership is like a marriage. Both are social-economic institutions. Both need chemistry to succeed. Both are really messy and messy when it comes time for the breakup. The child custody fight and the division of the assets may not always be equitable. Or, the team might do well together, the startup fail, and everyone parts as friends. There's lots of good suggestions here, and Paul Graham has written a number of insightful essays on the YC library and on his site. The misgivings might be a simply one of, "Well, if my project is so great ... shouldn't I be more picky about who I want to work with?" It might be some instinct tipping you off. Whatever the case, you'll have to look at both the strategic advantage for you and all the human motivations involved (including your's). Sorry I couldn't be more specific.