Not necessarily. I can understand moving one of EE/Bau because it is going to be expensive and also unlikely you can retain both once their contracts are up. I would imagine both would be seeking at least 15-20M (more so on the high end). That is a lot to tie up for DH players (I know Bau isn't that now, but he will soon be moved into that role in the coming years). Moving EE for someone like Quintana for example would be f***ing awesome.
Replacing EE with Smoak/Valencia platoon as someone mentioned above could provide near what EE does in terms of offense and likely better defense.
I am not going to argue with your last point cause I believe it. The only thing I worry about is "MLB ready arms" vs "MLB arms" are two different things which is something I think you would worry about as well? Plus arms bust / get injured often. Nothing wrong with adding something stable. On top you can move arms for more hitting too down the road if that becomes a issue and you find yourself with a access of arms.