Well, that's a whole 'nother question, with no simple answer. If it were purely a case of generating CP as quickly as possible, then one would simply work one's way down that list as steadily as one can (allowing for the fact that occasionally you'll have to build a lower but less CP-efficient level in order to get to the occasional higher but more CP-efficient level; or build a less CP-efficient building that happens to be a prerequisite for a more CP-efficient building).

But of course, it's not that simple. You can't generate CP without resources, and even if you get the CP, that's no good without the resources to build your L10 residence and expensive settlers. So your 'optimum path' has to balance CP generation with resource generation (and possibly with military competition as well); and that depends on how you want to generate your resources - simming, trading, raiding and various combinations thereof.

I guess the only guidance I'm going to give - the principal thing I've learnt from this exercise - is that maybe it's better to start off building lots of low-level buildings, rather than trying to achieve high levels of supposedly CP-efficient buildings. And that should give you the flexibility to pursue whatever strategy you like for resource generation.