I think the part that’s left out is “since they all can’t be right, yet use the same standard of authority for truth, the most likely scenario is that none of them have a reasonable claim to truth”.

The logic seems sound to me.

If they all look at thin air, and claim there is different kinds of magical beings, and as evidence they say they imagined it, isn't it reasonable to conclude there actually is none of the magical beings they claim? Since they use the same vastly erroneous process to make similar extraordinary claims.

As Richard Dawkins say: Extraordinary claims require extraordinary evidence.

That's why it says "most reasonable conclusion." If all of these religions have the same level of evidence of their existence, all have people who are certain that their religion is real and all others are false, and they all claim to be the "truth" then what's most reasonable?

Obviously it's possible that any given religion is correct about the world, but if you ask me which is more probable: that every human religion is wrong except the 1 that is correct, or that every human religion is wrong? I think I agree with the original quote

The reasonable conclusion comes from the vast range of possibilities of what is true, which is exponentially larger than the range of possibilities specifically expressed in the world's popular religions, even if we were to assume that every human being has their own understanding of what is true. The range of possibilities not conceived of by one of eight-billion human beings is vastly greater, so the chances of one person getting it right is akin to winning the lottery.

If we assume that any two people agree on religious truth, that number of religions becomes less, and the odds it is not one of those becomes even greater.

Note that there are about (not quite) 40,000 denominations of Christianity (and then all the non-denominational churches, some of which are megachurches that stay ND so they are not recognized as an NRM, which law enforcement presumes is a potentially-dangerous cult-or-sect) so we get very specific as to what religious truth is, and we fight wars or litigate over these specifics.

Considering the scope of the universe compared to the scope of life on earth (let alone human life), it's highly more likely the Milky Way galaxy (including the solar system and everything in it) is incidental to any divine purpose of the cosmos. The difference between the chances that we're special or important, and the chances mold under a specific Sequoia tree in central California is special or important is infinitesimal.

So even when we only consider theistic possibilities within the universe as we see and understand it, any popular religion that has a non-zero possibility of being true still doesn't have much more than that.

or they each see a different face of the same truth

I do think it's reasonable to say they are all wrong, but I agree with you, this logic provided in the image doesn't make sense.

It being impossible for all to be true, doesn't imply they are all false.

It's likely they are all false, if you subscribe to the philosophy of science, where without testable evidence, it's deemed unreasonable to assume something likely to be true.

The (in my opinion) correct opinion is that all religions are very likely false, because none have provided convincing evidence according to the scientific method.

And it's obviously the one with a god of THUNDER!!!

What, there are two?

Correct. By their very nature of certain religions being mutually exclusive, they can't all be correct, but they could all be wrong.

They aren't wrong because some are mutually exclusive. That's a non-sequitur. They are false or at least not true, because the evidence either falsifies the claims or doesn't prove them to be true.