Some of these programs also expect you to have X done before you show up. Like your GS courses. So the 16-18 weeks is only the flying portion. The X takes additional time. In the rest of the training world you can fly WHILE you're taking the GS courses.

CFI course? Maybe. MEL? Sure. PPL? Uh, I'm frowning. Comm/inst? I'm frowning. It's an area many of us probably don't have much experience with.