Yes, in USE all units have no numbers, including ground, naval or air force units. Moreover, all combats are governed by the same combat resolution table. It is good because it allows you to learn faster the game rules as you are using always the same table.
Why is this possible? The point is that you have several DRM (dice role modifiers) that are applied to units depending, for example, if you have infantry or tanks units. Nationality, among others, is one of the factors together with terrain or reduced units. Therefore, each number you usually see in counters in other games are embedded in the table computation using these modifiers.
It is a different way of doing the same in fact. Mathematically, you cannot escape to have a way to computing probabilistic results because all units cannot have the same strength. So by using different DRM for different units, you do not need to print specific numbers on the counters. Very interesting innovation in fact!