Request for Advice on Equity Split for Healthcare SaaS Company

Hello IndieHackers community,

I'm seeking advice on how to fairly split equity in a healthcare SaaS startup that I'm involved in. We have three key players, each bringing unique contributions to the table:

Tech Co-founder: This person initiated the company and has invested significant time and money. They have already dedicated 2000 hours to building the technology and will continue to contribute 5 hours daily. Also the tech co-founder already invested some money. Once the company reaches a bit more scale, the tech co-founder will work full time in the company.
Doctor Co-founder: Provides core ideas, identifies main problems, and has established connections with hospitals and other doctors. They have spent around 500 hours so far and will continue to contribute 3 hours daily. They were also instrumental in securing a distribution partnership.
Distribution Company: This entity integrates our software with their hardware sales, making it essential for our distribution strategy. We are considering an equity share based on performance targets related to sales numbers.

Our goal is to ensure the equity split is fair and motivates all parties to drive the company's mission forward. We are considering the Slicing Pie model, but we face challenges because:

The Tech Co-founder, by effort, might end up with more equity but the core ideas are brought by the Doctor Co-founder offers deep insights and significant value that are crucial for our growth.

Questions:

Has anyone used the Slicing Pie model in a similar context? How did it work out?
How should we weigh time investment against strategic contributions like those from the Doctor Co-founder?
What performance metrics would be fair for determining the distribution company's equity share?
Are there any best practices or alternative models you would recommend for this scenario?

Our goal is to aim for transparency and fairness, ensuring all parties remain excited about our shared vision. Any insights or experiences you can share would be greatly appreciated!

Thank you!