Can I change how opportunity territory-based assignment automatically assigns by opportunity owner?

No, you can't change the standard default application behavior when assigning opportunity territories to the opportunity owner. However, if you want more territories to be assigned to an opportunity, for example based on revenue, then as a workaround, you can create customer centric territories using a product dimension.

After you set up your territories, territory-based assignment matches territory dimensions and attributes to work objects. You can set up territory-based assignment to be completely automated, to happen on-demand, or you can use a combination of these settings. Territory-based assignment requires that you set up your territories and resource hierarchy, set profile options to configure assignment, and run assignment processes.

In addition, you can also use rule-based assignment to set up more rules used to assign resources to work objects. Rule-based assignment lets you capture attributes not defined in territory-based assignment. Once you set up the rules containing conditions that records must meet, then resources get assigned to the object when they match the rule conditions.