The key word there is might. Kompany is far superior to Skrtel in the air, and to be honest, I don't think Skrtel should've been the one marking him in the first place!
These 'habits' also help us at times though. I have to admit, I do feel uneasy every time Skrtel pulls someone's shirt at a corner, or manhandles them in a defensive position, but his fouls are actually quite tactical. He treads the line carefully, and only really commits fouls he needs to. His ball distribution is his weakness, in my opinion, but then, how many defenders can play the ball like Agger?
Skrtel stands a far better chance actually defending though instead of pratting about holding onto shirts. He's liability at set pieces, and often in general play.
he isnt treading the line carefully, he should have given away 3 penalties vs City.
His fouls arent tactical, they are because he gets himself in the wrong position and then has to foul to make up for it. That's just basic bad defending.