When do you give someone co-Founder title?

Version 1 was built by me. Version 2 was built by employee #2. Version 3 was built by employees #2 and #3.

We just went live yesterday, and any additonal hires will be "core employees". They were important to the build but not critical. Like I could get other people to build at this level too for the same market rates. Do emoployee #2 and #3 get co-founder title? I've already given them the max equity for such a situation at 2% each, even though they didnt request it, nor was it promised. I think we really trust each other at a very high level so I treat them like family.

Also, do I give the current main engineer CTO title? I was hoping to poach someone with a lot of pedigree to match our vibe and get the max valuations every round. Afterall, I want their 2% to count. In the space, we won on branding, product features, team and solution. As opposed to typical LLM companies, we dont serve customers our solutions. We use APIs, prompt management, query orchestration etc to serve the best industry solutions. Kinda like if Kaggle, Hugging Face and Wolfram Alpha had a kid. We create pipelines to do everything from fraud detection to cancer research.

Our TAM is massive with B2C, B2B, B2E, B2G implementations. I feel a CTO thats ex-faang or something close would bring a lot of "brand" value. We are already positioned to deliver the best product to the market. How do I make the optics match?

P.s I'm hiring exceptional MLEs, Data Scientists, Developers. We are building a "calculator on steroids" in the Data + AI space. DM me for more details!