Trying to think of the last time a 3 man back seemed to work in the EPL. Wasn't it pretty much a disaster for City last year the few times they tried it? Of course, if you commit to it rather than @#$@# around like they did, maybe it would work better. I'm not certain I would be ok risking points to learn it though. Every point is critical for our chances at top 4 this year.
And I also don't think Henderson on the right would provide enough width. Its ok with Johnson behind him since Johnson will provide the width (even if its head bangingly frustrating to watch).
I do think Henderson is carving out a secure spot for himself in the starting 11 though. May not last once Suarez comes back, but I bet he comes in for second half where we have a lead.