You choose the role of each partner in the company and the share of capital.
The CEO (Chief Executive Officer) will be Chairman, the other C-level positions (Chief Marketing Officer, Chief Technical Officer, Chief Finance Officer, etc.) shall be officers with the same signing authority and one may replace another (very efficient during vacations!). There will remain other investors who do not have a corporate mandate and therefore have powers only when voting on decisions at the General Assembly.
Investors consider that an equitable distribution between the partners is a guarantee of success and an equal level of commitment because everyone is encouraged to invest, and equality is the best engine. The only caveat is when there are two partners at 50/50 - pay attention to egalitarian distributions since a disagreement between partners could block the operations of the company and important decisions.
Whatever your decision, the initial distribution will evolve according to the success and the opportunities that your company will encounter, so we recommend you to spread the capital according to your degree of investment.