I am really skeptical of this method.
First, it requires the planets to be on a plane directly in line with earth. What are the chances of all the so called planets being in such perfect alignment with earth?
Second, it requires the planet to cross the star in the short time frame we are watching.
Third, what it that star had a huge sun spot appear, resulting in a temporary drop in light. Would that be counted as a planet?
1. Yup. There are far more than we can detect with this method. Since we can’t get them all, why bother? This by-the-way is a terrible dating strategy...
2. Yup. We have to look to see them.
3. Nope. The dimming has to repeat on a regular schedule to count.