OK, OK I get the 'chaos is a ladder thing' but it's still a stretch if you ask me. Littlefinger might've served his own interests but in the process of betraying Ned he chose a side and that side was the weakest one militarily to choose, it makes no sense. Say Stannis or Renly had marched on the capital and taken it, which was a plausible scenario at the time, you think nobody might've mentioned that Littlefinger was instrumental in the plot to keep a Baratheon bro off the throne?
Stannis/Renly/Robb would've likely arrested and tortured anyone involved in the whole situation and got the truth out of them. Hell, Varys would've probably volunteered the information to get Baelish out of the way. There's also the chance that if Stannis or Renly (Robb was too far away at this point) had marched on the capital right away, Ned would've been still alive and the Lannisters would've been forced to ransom him to buy time, at which point he would've been all 'It was that Baelish motherfucker who did me like that'.
So yeah I get that Littlefinger's aim is to spread chaos, I completely get the WHY but looking at it objectively with all the possible scenarios that could've came out of it he made a REALLY dumb strategic decision to betray Ned and it's only GoT being GoT that let him get away with it. this is completely at odds with the portrayal of him as an amoral scheming pragmatist. In real life having such overwhelming odds against you in terms of numbers and resources (Tyrells, Dorne, North, both Baratheons, Riverlands, etc against just the Lannisters) is suicide. Half of the trouble of war is trying to convince others to do it with you and the Lannisters were getting bodied on this front until the magic of fiction helped them out.
