Looking at the screenshot, the current options available to trigger a Smart Tag on an opportunity are very limited and not really designed for simple categorization.

I do like the idea of using a regular tag to trigger a Smart Tag, but in practice, that might also become difficult to manage. If there are a large number of tags, users have to remember exactly which tag triggers which Smart Tag, which creates confusion and increases the chance of mistakes.

In our use case, we create opportunities for many different reasons, and we've implemented the use of Smart Tags to organize and prioritize them quickly. What would make this much easier is the ability to select a Smart Tag directly, or trigger it through a custom opportunity field.

For example, if we could create a dropdown field with predefined options that match our Smart Tag categories, the user could simply select the correct option during opportunity creation, and the Smart Tag would be applied automatically.

This would remove the need to remember tags, reduce errors, and make the process much more intuitive for any user, regardless of experience level.

In short, either allowing direct Smart Tag selection, or allowing a custom dropdown field to trigger Smart Tags, would be a much cleaner and more scalable solution.