I wasn't saying that we can't get the scroll, but you make this sound easy, as if Hiashi/Hyuuga/other people aren't trying to get it. Hiashi isn't an idiot, he did get the Minami on his side after all. If he promises the scroll to one Clan and debt relief to some others, he might get all the support he needs. Also I am not seeing how we are in a good position to get the scroll even if we get a Pro-Goketsu Hokage anyway? Maybe Asuma want's to give it to [Insert Clan] for support?
We are going to send them a message anyway, so we will see in a few Updates (maybe), but I think we need to play more politics here and not rely only on Pangolin/Toad influence. Currently we are assuming that the Snake Clan cares about the Pangolin Empire and are interested in anything about them. We don't really know how far away they are, how strong they are (Orochimaru had some powerful stuff, maybe he shared a lot with them and empowered them?) or what their interests are.
Just really too many unknown parts, I mean, why didn't Orochimaru send his message via the Snakes to Jiraiya? If were lucky Oro was on bad terms with the Snakes and they want us immediately or there was some other reason (maybe he didn't want to be found by Akatsuki?).
On the other hand, promising someone a Summoning Scroll and getting it for them might be a way we could get want we want.
Example:
Give Clan X (Maybe we can get the whole Motoyoshi-Kurusu-Amori Block that way?) Snake scroll for support on Hokage vote, find Capybara, exchange.