I'm a fan of back fours, but not sure how the rest of the formation would pan out given the currently available personnel.
I'm also not convinced our defenders could adapt to the new formation in 3 days, given how they struggle to adapt with marking, tackling and passing the ball to their own team mates. We do need to change something at the back, though, so maybe the 4 is they way to go.
One of the side issues for me is having Miller as captain. I appreciate the idea behind it, but when you've had a drop in performance for a few games, having an angry old man for captain that yells in your face can sometimes be more beneficial than a nice boy with epic ball skills.