@6paths
Concerning the location. To be fair, we can't determine it's size due to us not viewing the whole hideout, but we do know that it's length is large enough to house the Mazo. When Jouki boy is in fruition, I see no reason as to why Nidaime and Sandaime can't fly to the highest point in the cave. So, not only are Nidaime and Onoki not feeling the full force of the explosion, but even if Jouki boy happens to effect them slightly, it can be tanked with Onoki's rock Golem, which was canonically proven to have tanked Deidara's explosion [
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]. So, not only is the impact not fully directed their way, and they can seek refuge in the upper parts of the cave (they'll still be affected, due to Jouki's range), but they can shake off the little threat it poses with the Rock Golem. No problems.
Sure, Muu and Orochimaru can locate the clam, but can they do so while being bombarded by Jouki boy's explosions and Jinton? Muu will be busy dealing with Onoki's Jinton, surely[
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]. Orochimaru's snakes are large in numbers, but as they're too packed together, one Jouki boy explosion will deal with them. Another difference is, these snakes were put to use in a large, open field. Whereas this time, they're gonna be even more scrunched together because of the cave's natural lacking of space. They simply cannot escape Jouki's range [
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]. As I said earlier, if a rock Golem could deal with Deidara's point blank explosion, then I'm fairly certain it could tank Jouki's undirected attack. As again, it isn't directly aimed at them, so they'll be able to force some distance between themselves and the attack.
Manda's just a waste of space here. One touch with Onoki Ultra-weight jutsu will leave it too heavy to even fight. Look here, one touch was able to make Muu sink into the ground [
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]. Now imagine what this would do to Manda. Manda would play no role here. He's way too large to
not get caught by this technique. Onoki can also utilize Bunshins in a similar fashion to that of his latest battle, and confuse the serpant, making his use of the weight technique a sure thing.
You forget, that that works both ways. Muu without Jinton, isn't much of a threat either.
Muu can stay invisible all he likes. However, Jouki boys numerous blasts will force him to reveal himself. Surely. Hiding does him no good, in an enclosed area. As you said earlier, "Jouki boy may affect Onoki too". Well, Onoki has a counter for it, Muu doesn't. If he gets caught, he's done.
Orochimaru can hide all he likes too. As soon as he does reveal himself, he's going to get overwhelmed by Jouki's staggering speed [
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]. Even faster when Onoki alters it's speed with his ultra light weight jutsu.