I'm pretty sure It was the system Koeman and Walsh were trying to implement with who they bought. Where it fell down was on the left side and the centre backs not moving up. Martina was at his best in that 3-5-2 set up and actually overlapped. It's just his quality was so low nothing much happened. So that didn't help either.
We just don't have the players to play it, and as mentioned above, and correct me if I'm wrong, we don't currently have a manager who knows the system.