We don't need an Overhaul. We have Messi Neymar Suarez still. We need a midfielder and right back and maybe a right winger if we use 4-2-3-1.
I agree with you that not much needs to be done to improve the starting 11. Our starting 11 is only a few changes away from once again being the best in the world.
However, I am more concerned about our squad depth. There are too many question marks over too many of the non starting players. Real Madrid don't seem to have this problem. This season, it does not matter which player Zidane puts on the field. They all seem to perform when called upon. This is a luxury we do not have. If we deviate slightly from our strongest 11, the result is most likely a draw or a loss.
I'm quite certain that if Barca played RM without each team using their 4 best players, RM would probably win 9 matches out of 10.