To be able to have comparable games we need :
- Railroaded civilization path or at least restriction from using DLC civs for those who have them since not everyone who plays the game will have access to those
- Fixed mementos
- Pre-settled capital (moving your founder changes which and where independent powers spawn and there's a big difference in challenge and opportunity if closest IP is a hostile military worth 100 prod when you raze it or a friendly economic)
- None can use legend-unlocked attribute nodes or legacy cards
- None can build DLC wonders
and even then the games won't be directly comparable because :
- AIs might act very differently based on a combination of factors that are not under direct player control. One player might have to divert a considerable amount of resources to defend against a multi-front war (but might get free settlements from the peace deals if they are good at it) while another one might have a perfectly peaceful game
- Later ages IP won't be the same for everyone. You can force the location of the first city but not where players and AIs place further settlements. As a result one player might be able to easily befriend 2 scientific CS while another one might see the only one on their continent razed by the AI on exploration turn 5
- Later ages resources don't spawn on fixed locations. By replaying some games in different ways during the Antiquity i've seen some (but not all) resources appear at different locations after transitioning to the exploration. That might, or might not, influence Economic games since some factory resources are spawned in the modern age (coffee for sure, maybe others)
- Culture games will be easier or harder based on where the limited number of artifacts spawn. When you research a continent, artifacts become available for everyone so if the 2 artifacts on your starting continent are right next to an AI or in the middle of your lands, the game won't be the same.
- ... there's probably a lot more
Some of those variables will have a much bigger impact than others. None will help me finish faster than Acken

Those who are interested in "ranking" can certainly see a trend after a couple dozen games but i don't think we'll be able to directly compare 2 players of roughly similar skill after a single game no matter how hard the team tries to limit the "background noise", there's just too much of it in Civ7