Per MoD's link, pick order (not move order) does matter. The example above, both p1 and p2 got a win, but p1 had first pick, p2 had second. So it makes sense that p2's win is worth more.
The link, https://www.warlight.net/wiki/Ladder_Ranks_and_Ratings
, also describes how you can compute ratings based on actual ladder data. Very useful!
The data for season 23 is at http://data.warlight.net/Data/BayeseloLog4023.txt
and presumably is updated regularly.