So basically you recommend to play the player, not the board? Sounds like bad advice to me.
I fully support any post-match analysis though.
I mean in general you shouldn't make important in-game decisions based on who you are playing, especially when it comes to picking.
this is partial true. In general you shouldnì't pick based on the opponent, but based on the board yeah.
But i am sure, ceteris paribus (same board) szew would make different pick agaisnt me than agaisnt another very good player, as he expect me going for some dirty counter.
I advice to pick based on the opponent ONLY if you know him very well, and you are sure what he is going to pick.