Sure, that’s probably a better model. I don’t see anything wrong with it and it has more parameters.
I just think P/E by itself is way too oversimplified and a pretty garbage metric when used in aggregate + historically due to things like interest rates, sector/business model skew, relative maturity of companies, etc also fluctuating over time. It’s like Week1 of value investing 101, not an actual metric by which you’d want to engage in value investing or historical analysis.