DB upgrade in Cluster (19c)

I have this generic (OS independent) question regarding Database patching in a Cluster (GI) environment.

Document 2368508.1, Database 19c patching for Cloud databases, states : "The GI version can be later than the DB component version."

That means exactly what it says, which is that the OH software version of GI can be higher than the OH software version of the Database OH's. Logically that is opposed to:

-being the same version, which is a no-brainer, but

-the Cluster GI version being LOWER than the Database OH version

In that same document, the GI gets patched first, which leads to having a higher version of GI at some point (even if you continue straight away with the databases).