As someone who regularly punches up, 2/3mill GP difference or 3+ GL difference (today being a rare exception) seeing my opponents score helps me massively. Infact without it I don't think I would have done as well as I have.
I understand the want for the change, seeing it does give your opponent or yourself a clear advantage in certain matchups where, as you described, you would be able to tell what they have used approximately but the cons for me outweigh the pro's to change.
Pulling out the calculator and figuring what battles need to happen with what limited squads I have is one of things I enjoy doing with GAC and has brought me many victories and saved me equally many hours of unnecessary battles where I couldn't win.