I think there is a lot of emotional angsting after this loss which is really knee jerk.
Our defence was not an issue until we got tonked by the Heart. We bounced back and did CCM but then got the same from Adelaide. We had kept it very tight at the back and that was in part because the guys in front of them did their job and stopped play getting there. It is obvious that Lia is not a DM stop gap which is not his fault - he is just not that type of player.
Sigmund and Durante are aging and are not the quickest but if they had the midfield in front of them that did their job, then all of those things are a lot less of an issue because they get protection from guys who are doing their job. At the moment, opposition stare solely at our CBs because that's what they can see. There is no defensive line between them and the CBs. Break that line with some slick inter play (or allow players to hit shots in from outside the box) then yeah, Sigmund and Durante are going to look past it.
I'm not a Sigmund fan but I don't think its fair to go 'well you are past it' when the help he is meant to be getting from the guys in the DM position in front of him, he is not getting. Its effectively a black hole position for us on the field cause the guy that is in there, is not his natural game and I think it is a little unfair to smash Lia for that when its not his game. He has been asked to play there and he has gone 'ok boss'. If Leo was asked to play there, he would go 'ok boss'. Both would be effective as each other in that role.
This points back to recruitment. As JD reminded me, we lucked into Riera and prior to that, we were content with Manny and Lia. Ernie needs a DM recruit this winter pure and simple and these defensive woes go away.