When we were considering how to categorize Guest Speakers, a key factor for us was that it was common that Guest Speakers would only deliver 1 or 2 sermons at a particular church. This means that it would be unwise to categorize the speakers at an equivalent level as more consistent and permanent speakers.
We were concerned that when people saw all available speakers in the right sidebar that the primary speakers would be lost in the many guest speakers. This would become more of an issue as the years go on.
Some churches have had dozens and dozens of speakers over the years, but their primary staff still receive a prominence in the hierarchy as these will be the most searched speakers.
In the end, the solution we felt worked best was to add the Guest Speaker’s name to the description field of the sermon. So in other words, use that field to write “Joe Smith joined us to talk about…” That way the speaker will still receive recognition for their sermon.
Here’s an example of how this would look on the website: