Just like when nations form a coalition (partnership) against a common cause there’s always risk to that contributing nations blood and treasure. And lets not kid ourselves, it’s that RISK which you are refereeing to. So, that said, I would not recommend starting that partnership as a 50/50 division. Even your gut instinct in your question is saying that. So, if not 50/50, how do you? One way is a common goal approach supported by a task-to-purpose objective base. For example, I recently consulted a small three-person partnership cell phone repair business. These young folks had no shortage of people with broken glass phones. They had the idea, they had the model, but they didn’t have the common goal. They convinced themselves that each partner had equal stake in “bringing something back to the business”, or “you need to do this, you need to do that”. That’s not strategy. What I had them do is free think and write down every task they could conceive of. Then I had them agree on their mission statement for their business. Once those where visible we simple placed each task into a prioritized list. Hence, task-to-purpose and moving towards the business objective. The partnership was forms based on a common goal. Not a 50/50 equity split. Sure, they’re all equal partners, but they all have stake in ensuring the objectives are accomplished. Just some thoughts from the Spartan Team.