Wait, no, that’s bullshit. You can’t say “he’s literally a liberal” and then just say “because I know one when I see one.” You’re proving my point: you only think he’s a liberal because he’s said things against Trump.
On average, the members of our military are way more conservative than the average American, and that’s even more true for their leadership. But Trump has consistently alienated them, and it’s no surprise that many of them are disgusted with him. That does not make them liberal.