You are right, with a bit of a caveat. Once the HUD has a large enough sampling of a particular opponents range and tendencies, YOU have some of the information you need to make more informed decisions. Naturally, the HUD does not tell you how to play a particular opponent - that is up to you.
The HUD is like the stats people for your favourite sports team - it tracks all the tendencies of the opponent, like knowing the chances of your opponent kicking with his left or right foot, depending on the situation. Helpful info, but you are still the one who has to figure it out and apply it.