Makes sense. Speculation? You can clearly tell when one is running low on chakra and stamina. There was never any indications of such. Water Shockwave helps him in a plethora of ways if Sasuke wants to remain on the surface. If he opts into summoning the hawk, he's only prolonging his inevatable defeat, so doesn't make a difference to me either.
Water Shockwave, WD, Subteranean Voyage, Mizu Bunshins, and Samehada makes everything you listed complete non-factors. Ignorant argument in regards to GSB and susano'o. Kisame was stunned to see that GSB wasn't instantly growing bigger after swallowing Hirudora (implies the absorption doesn't take time at all). He never once questioned if the amount of chakra was too massive for it, he questioned whether the attack was even chakra based in the first place. Why? Because the stronger the enemies technique, the stronger GSB gets. Stated in the manga and databook. But somehow, anything above V2 susano'o is an unquantifiable amount of chakra that breaks the threshold of shinobi, and warrants a no limit fallacy due to a lack of feats. Solid argumentation, with great reason too. Subteranean Voyage only turns the ground around Kisame into fluid, and there is no reason for Kisame to be swimming on the surface of the ground. Susano'o arrows aren't reaching him. Especially with bunshins into play as well.
Na bro, that's not what I mean. 100% Kisame might have lost like 10% chakra from creating that amount of water, and you wouldn't get any indication that he lost that amount of chakra. Continiously shape manipulating the water would also take quite some chakra over time. If Sasuke uses Amaterasu for the first time in a fight it might take, say, 15% of his chakra, but you wouldn't notice any 'dent' on his chakra. Same case here. If Kisame tries to manipulate a large body of water for an hour straight then he'll end up low on chakra.
Absortion takes time, he only was shown to be surprised after the Hirudora reached 10 meters inside the GSB [
You must be registered for see links
]. He doesn't need to question the amount of chakra for there to be a limit, because there is obviously a limit (it's not absorbing TBB's, Juubi lasers, etc, nor is it absorbing v3 Susano and over.
@bold, Doesn't matter what you say, it's no limits fallacy to suggest it can absorb huge quantities of chakra. And hell, I'll even drop this argument if you want and say PS gets absorbed, but that won't matter because Susano will never be inside the GSB in the first place. As shown, GSB needs to consume the jutsu. Sasuke using a V3 Susano or v4 Susano extended sword (yes, he decides how large the sword is) cuts the GSB with a slash (it's barely ever, if ever, used a thrust, which is the only thing that'd get absorbed). A slash will destroy the GSB since the GSB doesn't absorb from outside, it only absorbs anything
inside it. Bunshins are irrelevant if Sasuke is airborne, and get recked due to them being 1/10th power. And lol, what? All the ground he passes turns into fluid. Unless you are actually trying to suggest the ground returns to solid once he passes it.. lol. And Kisame is incapable of staying under ground for prolonged periods of time, he needs to breathe after all. Once Sasuke sees that Kisame's going back to the surface Kisame gets one shotted. Using Aoda can easily end up destroying your entire Subterranean Voyage argument as well, since Aoda fishes him out with his mouth.