You make it sound so easy but it's not.Making someone hurt his or herself in the literal sense isn't something that is possible in most cases.And the information naruto got from the hachibi was descriptive enough to basically tell you what to do;especially the part about the hachibi and the raikage passing out with their jutsu still activated.That part pretty much gave away how the raikage got that scar on his chest.Naruto didn't have many blanks to filled.The hachibi didn't remember how the raikage got hurt, Dodai told naruto that scar was the raikage one great shame that he didn't want to talk about;throw in the information on the hachibi jutsu and the raikage jutsu both still being activated and the story is clear as day.As for shinobi with high IQ like Shikimaru and Shikaku figuring it out, that might be true or maybe not.They are smart but not mind readers.During the shikimaru and Asuma battle with Kakuza and Hidan , shikimaru could think up a way to win that battle because he had no prior information on them.Now his intelligent did allow him to figure out Hidan ritual, but that was only after asuma took some serious injuries.That would also be the case with the raikage, no prior information and unlike hidan, the raikage speed will play a major factor in how much time he has to think.The same for shukaku, he's smarter than shikimaru, but he seem perplexed about the revived muu and I doubt if Onoki wasn't there, that he would have found a way to take on Muu's Dust Release , nor could he have found a way to make Muu hurt himself with Dust Release.
As for the clones, maybe The raikage does maybe he doesn't.But if you can speculate that intelligent shinobi can find away to make a kage level shinobi hurt himself without any indication of how, why can't someone speculate on basic jutsus a kage might have.Under the circumstances, it would be much more passable for a kage to have a clone jutsu, then it would be for any shinobi to figure out the how to make a kage hurt himself with his own jutsu without any information on the kage.
You took what I said out of context for the most part. I said figuring out how to defeat the Raikage is simple, not that it would be easy. As I've said before, making somebody hurt themselves is something taught in most martial practices. In this case this it is on a higher level but the concept is still the same. It's easy to figure out what you have to do (i.e get him to hurt himself because everything you've tried doesn't work). I'm in no way saying it would be easy for Konoha to acomplish this goal but it's easy enough to figure out what you need done, get him to hurt himself.
You're example with Muu wasn't a very good example either, it appeared as if Tsunade and A had information about Muu. Although she didn't say it out front she did say "The second Tsuchikage is no ordinary shinobi...the old fenc-sitter's the only one who could stop him" Since the whole camoflauge mastery had already been established what else could she be talking about. It was finally A who actually talked about the Bloodline Expansion. So Oonoki wasn't even the one to tell them about it, it was two shinobi from another village, take note of that.
Also about the whole thing, remember that Naruto's clone was fighting the Raikage, not Naruto himself he's more then enough to handle or at least distract the Raikage while a plan is formulated. During Pain's attack the Anbu were deciphering all the infromation they had recieved about Pain while Naruto was fighting. I will say it again and I will continue to say it. Deciphering what is needed to defeat defeat the Raikage is easy, going about it isn't but it is capable, as we've seen.
Speculation on the grounds of no indication is not good, you can speculate if you have valid reason to. What reasons have been given that the Raikage can use any sort of physical clone?--
What reasons have been given that Shikamaru and Shukaku are capable of figuring out the weakness of the raikage?--Shikamaru has an IQ of over 200 as stated by Asuma, he's a strategist and he's put his mind to the test occasions such as the Hidan and Kakuzu incident. Shukaku still manages to defeat his son in shogi, which is a game of stratigics and Shikamaru and Shukaku's basis for their strategy planning (as seen when shikamaru planned how to defeat Hidan). Shukaku is leader of the jounin in Konoha and the head strategist at Tsunade's side and his demonstrating his stratigical abilities on the field. Shikamaru is the proxy general for Gaara's division...Do you see. That gives us valid reason as to why people may believe that, at least those two, are capable of figuring out the Raikage's weakness, because they specialize in that category.
Summery:
~Figuring out what is needed to defeat the Raikage is easy, acomplishing isn't
~No indication or probably cause says the Raikage has a clone jutsu
~Muu's abilities were explained by Tsunade and A, not Oonoki so he wasn't needed for that. That being said Shukaku could've come up with a strategy with the aid of Tsunade, and Tsunade is in Konoha to help so that would throw out that example.