I agree, crates need increasing for the higher levels - a top NoD or GDI of power, crystal or tib doesn't scratch what is needed for upgrading base, army or defence units at the higher levels.
Linking the level of the crates at the higher levels to the level of the camp instead of the players with it reducing every time the player takes a run at it. So if attacking a level 70 camp with a crate but it takes 4 runs then the crate value is reduced each run after the first. That way lower offense levels won't gain anymore than at present. Probably a lot of coding involved so probably not a likely improvement!