Just revisiting the goals in the OP. Had a look at them again. One thing I'll note is that Meyler's for Hull has to be taken off the list as it was not from a set-piece; the move originated from a free kick in their half, but there were several passes before it went in the net, so it's not really correct to attribute that to a set-piece. Similarly, we can't really talk about set-piece defending and penalties, as that's a unique situation.
Given that, it looks like we've conceded 9 set-piece goals in total, and only 7 in the league. We've conceded 21 goals in the league, so that means we're conceding set pieces at a rate of 33% of goals, which is fairly average or slightly better than average. So statistically, we are not doing too bad. The real problem is HOW we concede them, because they are almost all preventable. Sometimes a set-piece is well-worked, or the opponent is powerful and good in the air (Lukaku, Kompany). But a lot of it is just plain football sense, or a player problem. If we look at the 9 set-pieces we conceded in total, and look for common denominators in terms of players making an error, then two names crop up. I won't name them, lest I be accused of scapegoating - having said that, most problems in football are player problems once the first whistle goes. In our case, we have three common denominators - the two players who have made the errors consistently, and the manager for not doing enough quality work on set-piece defending. We could probably improve our stats on this, though, by at least replacing the two players in question - given that we won't replace the manager, and he doesn't seem to put too much stock in working on the issue tactically.
