This book has a decent premise, but needs a lot of development and research.
Firstly, all that vigilante justice is going to get people in a lot of trouble. The book would’ve made a lot more sense if their commanding officer had ended up as the community’s police chief, or in some other way an official. As it stands, there’s just a ragtag bunch of veterans going around, killing people and blowing shit up. It’s more than a bit far-fetched.
Secondly, the characters need a lot of development. I highly doubt that somebody listening to an MM romance audiobook for five minutes is going to suddenly realize that they’re attracted to members of the same sex. Instead, I think that Maddox was going through some sort of emotional crisis due to his PTSD, the loss of his troops, and leaving the military. Losing all of his friends, and his only support structure, he turned to any sort of emotional ties he had left… And mistook that intense need for emotional connection with a physical connection. Also, Maddox, excepted, same-sex intimacy, awful easily. I would have expected some research, self exploration, and awkward moments.
Thirdly, you don’t just get to leave the military whatever you want to. It was good for Maddox to have to spend some time on his own when his new lover went back into service. It better establishes the relationship as authentic, instead of an effort to hold onto any ties to his past.