It's a lot of decent pieces of the jigsaw, just from lots of different jigsaws.
Sigurdsson is good on set pieces and crosses, but we have no real aerial threat.
Sandro is quick, but we have no one who can play through balls.
Keane is a good defender, just about as slow as any player I can remember.
Walsh has to take fair amount of blame, but for me, the majority of blame still lies with Koeman. Walsh identifies players, but he's working and trying to fit with managers idea and way of playing. It's up to manager to instruct and think about how it fits together, whether it will work. I think he just thought, yeah buy lots of talent and I'll work something out. He was reasonably hands off in regards to recruitment, hence his complaints a couple of months into season.
We just can't do anything about it until the next window.