Possibly, but I personally don't think it's that simple. If it was, then our lack of a plan B is inexcusable with the squad we have. We should be able to change things up and remain competitive if injuries disrupt plan A.
I think we would have had the same struggles had James and Chilwell remained fit anyway. December, January and February are often poor months for us these days and I don't think that would have been all that different even if James and Chilwell were fit. It may not have been quite as tough as it has been at times, but I'm not convinced that we would have kept up with City and Liverpool. Just look at James form in the month before he got injured, he wasn't playing well at all, I remember mentioning at the time. The injury took him out of the firing line, but he was fully part of the squad that's form had suddenly nose dived after Chilwell's injury.