I could only reply: "I don't know. If you have a problem with quality, you might need more. If you have a problem with the maintenance of your tests, maybe you need fewer. However, if there is no problem, you're probably doing the right thing."
This one can be abstracted, away from the specific issue of test automation.
If there is no problem, there is nothing to fix. But how do you know if you have a problem then?
Here is a simple suggestion: Collect data. Then, decide based on facts.
This is an example of how you can track:
Each time your team encounters an issue and spends time with or because of it, make a mark. Your result might then look like this, depending on which activities you are tracking and how you track:
In your retrospectives, you can simply look at the numbers and ask the following questions:
- Does this make sense?
- If not: What should we do about this?
- Will we gain more insight if we get more data in the next iteration?