Nobody has the same definition for the CTO / VPE split. If I search "CTO VP Engineering" on Google the first result is https://www.ivyexec.com/executive-insights/2015/cto-versus-v... which defines the CTO as someone in charge of a small team doing "technical exploration". At other companies that role would be something like "Head of Research".

Maybe it is time we stop using those titles. I personally saw that confusion cause serious issues at at least two companies.