Are you being deliberately obtuse?
Well let me edify you anyway.
Nope
Firstly, the only factual case that can be made for a single champion at MW is that for Alvarez.
As I've pointed out previously there are in fact only two ways of becoming the 'true champion' -- your choice of words not mine.
Undisputed and lineal.
Neither of those ways is either speculative or arbitrary. They are -- sans a disputed result -- definitive.
Whether there are only two ways of becoming 'true champion' or whatever term is used depends largely on how the terms are defined, and I see no good reason why having a case for being the true or only legitimate champion of a division
requires one to be either the lineal champion or undisputed champion.
Now you can wax poetic about 'conceptions' and 'limiting vagueness' all you want, but every example you try to give is either the aforementioned arbitrary or speculative.
There could be quite logical reasons for choosing number of title defenses as the criterion. Lineage itself is pretty much useless after one fight, as someone could win a lineal title then just keep the title hostage by facing clubfighters once a year. If the focus is on number of title defenses made, it puts pressure on top fighters to be active and consistently face ranked foes if they want to be champion. Moreover, political and business impediments that prevent deserving fighters like GGG from getting a shot at the lineal champion wouldn't be as significant in this case, as contenders can gain ground on the champ even if the latter keeps evading them. So the title would serve a broad, instrumental function while the champ would be an embodiment of regular, fairly high-level activity.
There are also computer-based rankings available today that don't depend on lineage or number of successful title defenses. Once the initial values are systematically set these produce objective results, so perhaps they could be used to determine the champs as well (maybe we could come up with averages of their rankings too). Incidentally, Alvarez would be MW champion if we employed BoxRec's rankings, but it wouldn't be based on his lineal champion status, and in certain divisions (e.g. LHW) the champion wouldn't be the current lineal title holder.
Of course there are flaws to these methods too, but the same can be said about going by lineage. I don't actually embrace any of them right now and I think that people should generally place less weight on who is champion and who isn't.
Factual is concrete. Did Alvarez beat the man who beat the man,etc? Yes. It's a matter of fact.
Right, so the title defense method is concrete too.
Whoever beats Alvarez within the MW limit can lay claim to the lineal middleweight championship. As to whether that person is better than Golovkin? Well we're back to speculation again aren't we?
No shitt they can lay claim to the lineal title; that's not the same thing as the lineal champion being the only legitimate champion in the division.
As for the speculation, doesn't that apply to the Jones-Calzaghe example you mentioned earlier? If so, why did you mention it?
Logical, reasoned, factual. Consider yourself edified
I'm sorry Taki but it seems that I'll have to look elsewhere for that. And by the way I don't have much of a problem with people referring to the lineal champ as THE champion, as long as they don't act like that makes a lineal champ any more credible at the weight (and a non-lineal champ any less credible at the weight) than their quality of opponent and performance merit. Unfortunately, it seems to me like many people place too much weight on lineage, and would see a lineal champion as being more credible than a non-lineal champion in the same division even if the latter had a much deeper resume and consistently performed better.