Could be that was his claim, but I'll let him make it rather than rely on your say so. No offense intended.
First, I concede that if you craft your analogy so tightly that there can be no question that the elements being compared are properly analogous for the purpose of your argument, then your argument may not fail for being an analogy. In your hypothetical, you have made the comparison practically tautological. It's more an argument by example than by analogy.
Second, your hypothetical argument is an inductive prediction from observations of like things. Which is fine. I'm not claiming that these kinds of predictions always fail.
The kinds of arguments I'm talking about are attempts at logical proof by analogy. They're not predictions or estimates, but claims of fact. "Because X is true, Y is true by analogy with X. Therefore you must accept my claim that Y is true."
Those are the kinds of arguments we see here: Attempts to induce acceptance of one claim, by making an analogy to another claim that is (assumed to be) already accepted.
And they fail for two reasons. One is that arguments by analogy (of the kind I'm talking about) are open to dispute about whether the elements being compared are properly analogous. Is X really analogous to Y in the way necessary to prove your claim?
The other is that the analogy moves away from thing itself. Any truth you may express via the analogy is only a shadow cast by whatever truth is in the original thing itself, in its own terms. Analogies are good for introducing neophytes to an unfamiliar concept, opening the door to new ideas by means of an idea already familiar to them. But true mastery must come from understanding the new idea on its own terms.
The moment you start arguing the analogy, you have moved away from arguing the thing you had intended to prove. This is a mistake.
If the claimant cannot express and prove their claim in its own terms, they have failed themselves and their audience. Therefore I maintain that arguments by analogy always fail, in the context of rational debate. If your goal is to convince your audience of the truth of your proposition, you must prove that truth itself, in its own terms. Not in terms of some other allegedly analogous truth.
But that's just my opinion. And you know what they say: Opinions are like bicycles--women have 'em, and fish don't need 'em.