I don't really get whole "Jasnah is in order #2" theory. My problem with it is that Jasnah is shown to have two powers, Soulcasting and that lightning thing in the alley. Kaladin's two powers are Gravity (basic and reverse lashing) and Atmospheric Pressure (full lashing). If adjacent orders share one power, then Jasnah and Kaladin can't be in adjacent orders because they don't share a power. I don't see how the lightning could be a part of Soulcasting, since it was done at a distance and didn't involve transformation. And unless there are more powers in order #1 that we haven't seen yet, I don't know how those two could ever be adjacent.
While we don't know for sure what orders Jasnah and Shallan are in, we know they have to be next to each other because they share the Soulcasting power. And looking at combinations that are next to each other, Shalash and Palah is the best fit. While "Giving" might not seem like a primary Jasnah trait, Shallan was never very honest, she just needed to be honest to those spren to access her powers. I think it could be the same way with Jasnah, it's something she needs to do for a stronger connection to her powers. I could even interpret her killing those men in the alleyway as giving something more to Taravangian for being a gracious host.
When Shalash's order fits almost perfectly for Shallan, and Palah's fits very well for Jasnah, it's hard for me to come to any other conclusion. Brandon might pull a twist and show that they actually belonged in other less obvious orders, but that would mean that he planted a bunch of red herrings along the way to mislead us. And while I can see him doing that for a major plot point, for something like this (which we're hopefully going to find the answer to in Words of Radiance) I'd find it odd.