I know of a sefer that talks about a Jewish army before Moshiach, it’s called the Torah and Nach. To fight Amalek, Moshe didn’t ask everyone to sit and learn. Preparing to conquer Canaan, yehoshua didn’t order Art Scrolls, he formed an army. Whenever Bnei Yisroel was being oppressed, Devorah didn’t fight back by having everyone sit and learn. King David had armies etc
