If you know that the tech cofounder is about to leave, then probably they should have options.

A cap table (with founder shares) has usually Equity and Options. The main difference is that Equity is hard to give and hard to take away (think: Shareholder agreement etc...), Options (easy to give, easy to take away).

The above question would probably be never be asked due to a number of reasons.

Without funding, it will be very hard to attract a CTO after a tech co-founder leaves.

Fundable startups at very early stage are usually composed of 2-3 founders. This is to due with many factors.
If 2 people, then one should have a majority, one minority. Someone has to lead (decision). With 3 founders it is different. If you have more then 3 founders, the startup might go into too many directions. it does not mean it does not happen, but you might be creating a barrier (IF YOUR GOAL IS TO RAISE MONEY).

It is very important that your MVP is validated with customers and gets traction. Traction is Users or Revenue.

I suggest you learn how a cap table works and if you do some simulations you will see how to answer this question.