Hmm, yeah, gamedevs might not be the ideal audience for explaining astronomy science questions :P

I tend to agree with your flaw description, it sounds logical at least.

However, when they make an announcement, do they exclude the possibility of having more planets than one? Ie, isn't the wobble method not just a crude way of finding a planet, whereas the transit method (no idea what that is), is a more precise method?

I mean, you do need at least one planet to get a wobble, right?

As for more planets, given the results of the transit method, it is fair to assume the 'wobble' stars also have multiple planets, like you believe too.

Could the wobble method confuse several planets with one?

Theoretically, it can, you can even eliminate the wobble, by having two similar planets rotate with the same speed, each planet counteracting the pulling force of the other planet. That is a false negative though, and not a false positive.

I think a false positive could be created by having two or more planets pulling on the star in the same rhythm, which mostly means (I think) same cycle length of a 'year' for each of the planets. If not, the planets will make the star oscillate at different frequencies, and in theory you could notice that, but no idea how good the detection methods are, it's easy to loose such information in the noise. I think it's fair to assume that having several planets with equal 'year' length around a single star isn't very likely.

Another item is mass of the planet. Bigger planets pull harder, sort of obliterating movements from all the lighter planets.

So my guess is, a wobble implies having at least one planet, where they make an educated guess on weight and year length of the biggest planet. When you go there, you may (perhaps /will/, if you look at the transit method results) find more planets, and theoretically, you could find some sort of duo-planet but size wouldn't be far off, since mass runs in N^3 to size, so half the mass is still mostly equally big.

If duo-planets exist much, you would find them with the transit method too, wouldn't it? Any idea on how often that happens?

Edit:

Pondering about it more, I think duo-planets don't exist. Assume you have a duo-planet, where the second planet runs behind the first one by 1/4 of the cycle. These things are the biggest planets there (or the wobble method wouldn't find them), so they must pull on each other too. That means in a few million years, they crash into each other, as there is no counter-force to prevent that. Given the age of things flying in the universe, such things would have happen a few eons ago.

But I distrust the wobble method for reasons stated below.

That's fine. Right now they're just sighting and estimating for stars that are so distant we will not be able to do anything about it within your lifetime.

Right now the farthest probe away from Earth -- which was bounced off several planets to reach a higher speed -- has taken 30 years to reach the edge of the solar system. Scientists have figured out how to make even faster probes, right now they could make that same journey in about 20 years instead of 30.

At that same rate, it would "only" take around 17,000 years to reach the nearest one for the 4.2 light year trip.

So barring some discovery that allows traveling a much higher travel rate, say around 0.1c, the claims about exoplanets are nothing more than exciting hype, much like people 5000 years ago looking at the seas of the moon and giving them creative names. Maybe someday someone will figure out a way to reach them, but for now and the foreseeable future they're just talking points.

I think astronomers use frequency-domain analysis techniques to find periodic signals in the doppler shifting of the star, this would allow the detection of multiple planets if a wobble was detected at different orbital periods. They can isolate the signal for each planet and use that data to determine various properties of the planet(s). The main limitation of the wobble method is that it's harder to find small planets within the noise, while big planets show a stronger signal.