there are some books out there detailing mission patches from history, if you haven't checked them out I would suggest it.

Here's one for space flight missions [0], but the military books are much more interesting imo.

Also, if you're just into patch/military design, check out the art books for the Ace Combat, Armored Core, and Metal Gear franchise video games.

[0]: https://www.amazon.com/Human-Space-Flight-Mission-Handbook/d...