Personally, I think that trying to make bikes with differing geometries match exactly is both futile and unlikely to produce the desired results (those being comfort and performance). The most common denominator is saddle height, but even that can vary a bit between two "perfect" setups. It's because what matters in fitting is dynamic, and many factors come into play as you pedal the bike. If you have greater bar drop, that might influence the saddle angle, which might influence the saddle height. Being a touch more stretched out may mean you need to be a touch higher... or lower. It all comes into play, and what matters is what happens when you are pedaling, not when you are in a static position. Different geometries will handle differently, and that may mean that you want to be further forward on one bike than another bike with different angles/wheelbase/fork/etc. You are seeing that when you expected to see the front axle in the same place and it wasn't. What matters is the handling and how you feel when riding the bike.

Proper fitting is a process, not a single event, and the 'perfect fit' changes with your fitness and goals, which may also differ from one bike to the next. IMO, you can't just peg the relationships that work on one bike, and apply them to another.