Everyone will take the DLAB, which supposedly determines how capable you are of learning a new language, but you also have the option of taking a placement test of a specific language (do it). Score high on the DLAB, which for me was very hard, and you will be more likely to be put into a strategic language. So yes, "strategic" can be replaced with "really challenging". From what I know, getting into Spanish is not easy, because so many people have background in the language. But if you do have background in a language and they put you into something else, there's nothing wrong with trying to change it, especially a strategic language. I know I scored terrible on the DLAB, but since I took the placement test of a strategic language and validated the first year, then I was put into the language. So in summation, if you know a certain language, don't worry too much about the DLAB, and focus on the placement test.
If you want to minor in a language, you need to achieve the third year class of that language. So if you validate the first year of a language, you only need to take one year of language to fulfill your language requirement at USAFA, and two years to minor.