Android Question Separate FireBase Projects for each apps/games or just one FireBase Project for all my apps/games ?

As per Firebase site,

• Number of apps per project
  While there is no restriction on the number of apps within a project, adding an app can create one or more underlying OAuth 2.0 client IDs. There is a limit of around 30 client IDs that can be created within a single project.

Say I am creating various games like match-3, runner, quiz etc. Now since all the games do not share same logic and display, do I need to create separate FireBase Projects for each to add AdMobs codes to them ?

The site says problem of "OAuth 2.0 client IDs" which actually I do not understand, if related to showing Ads or not.

What is best practice ? from the experienced members here.

Regards,

Anand

PS. I also do not like Ads but time is tough and looking to make a living.