My suggestion would be no one should be CTO at the beginning. Limit titles at the start since it gives you flexibility. Lee Holloway wasn't "CTO" or "VP of Engineering" when Cloudflare started; I was "Programmer".
Anyway, I am flexible John! Totally onboard to give up my title if you are interested to come over and help us RevenueCat go public ;)
Except that wasn't true... Matthew had the title CEO (because someone needed to be CEO) but Michelle's title was "Head of User Experience".
However, when I was on a roadshow through Silicon Valley, almost everyone I met (a few tens of people over a month) kept asking "so, what's your title" and writing it on the title-free business card I just gave them. One of the conclusions of that roadshow was that business cards HAD to have a title; I added "CTO", one of my co-founders had 2 stacks ("VP Product" and "VP R&D") which he used depending on who they were meeting. We both did the same kind of work.
My conclusion would be "don't have titles internally - but have some consistent externally visible titles for those people you meet who need them".
I haven't needed to do a roadshow since then, I don't know if that's still common in the valley - but that ritual of asking for my title and writing it on the just-received title-free business card was so prevalent, that I assume some people would still look for that.