With respect you didn't read my post. I said, 'management skills aside', all those events just happened. There are certain things as a manager you can't control and sh*t seems to happen to Wenger more than most. Like 3 CBs missing or 4 injuries already before the first game had ended, and that doesn't include his long term ones. He didn't go out and kick Gabriel himself ffs and these are not excuses.
Coutinho's free kick was inch perfect. He could take 10 of those and only one would go in. Walcott could take 10 penalties and normally 7 or 8 would probably go in. Wenger can't control these things.
You can only blame a manager for decisions he makes, like not buying enough quality players, or making sure your most confident player takes a penalty before the match, which is what you're talking about.
Injuries to CBs were out of his control, but I think what really grates people is that the injury to Mertesacker should of been redundant as he shouldn't of been anywhere near first choice this season.