Since he assisted in organizing Gallipoli in WW1, was he afraid that the allied forces would be forced to dig in and face a stalemate in Normanday similarly in WW2?
Allied commanders, including Churchill, were confident that D-Day would not end up like Gallipoli, thanks to the experience gained from the many amphibious operations that had been carried out earlier in the war. I have answered questions on the lessons learned from these here and here.