LCS was, and is, an experiment, to see if ships can be built, like legos, in modules. The jury remains out.
Now, abck to DD-1000.
They designed the DD-X/DD-1000 concepts out without much examining the modern role of destroyers. Which is why DD-1000 is really more of a Crusier than a DDG.
So, we are unlikely to see a Zumwalt class as a plane guard in a CBG. Operating as an Aegis hub for coordinated air defense, maybe, but not as plane guard. Probably not going to be on the forfront of ASW, either (VDS gear is not stealthy).
For 2¢, I think we need an independant cruiser class, CG; an escort class, EE (suitable for both convoys and CBG); and a fire support ship FS, a ship truly designed to operate in the littoral, while being ocean-going. But, I'm old, sensible, and done on 11 NOV 16, so any opinion I have is just that.