Well, kind of. If the big flashy wizard is still doing big flashy wizard things instead of lying prone behind total cover and letting the Sharpshooter handle it, he is in my opinion engaging in incorrect counterplay.Plus, even then, the sharpshooter is only picking off at most a number of hobgoblins equal to their attacks/round. That gives them a fair bit more time to make the front line PCs' and the big flashy wizard's lives difficult.
Then again, players always do counterplay wrong. And their PCs usually survive anyway, because 5E's "Deadly" is calibrated to be not-too-deadly.