European Orbiter vs. American Rover

Today I found out that a European orbiter had found water on Mars.

When I noticed this news, NASA shouldn't have sent the rover to Mars when it's going to take a while for it to stop bouncing and rolling and it still hasn't unfolded itself. When the rover unfolds itself it could take several days to do that, and yet the Europeans are already ahead. All what they did was send an orbiter to Mars which is a lot more efficient than sending the rover because it can gather more info since it's like looking at a map (of water vapor) - Alex