Maybe you can imagine it like an analogy. Imagine you saw a very big thing. Now later you see that the thing is still big, but it's a little bit less big. Someone might even say that it has become smaller. But this is a paradox because even though it is big how can you say that it is smaller, when the word 'smaller' itself contains the word 'small' which is the opposite of 'big'?
I'm confused why your analogy is a paradox. "Big" and "small" are always in reference to something else. In the first instance where you are establishing that the "thing" is big, you are referencing something unstated (perhaps the size of the observer). In the second instance, you are referencing the old size of the "thing" when you are establishing that it is smaller. Because the reference has changed, there is no paradox to it being both big and smaller at the same time.
Less aggressive doesn't mean not aggressive. It's a comparison. They're far less aggressive than most any other animal that could give you a bad day is. I'd rather run into a wild elephant than a wild wolf, lion, hippo, giraffe, etc.
