On the Borg side, the Borg Queen is often a central character. She is the one who commands the Borg collective and devises the plans to assimilate the Space Marines. For the Space Marines, you might have a tough and experienced sergeant. He is the leader who has to make difficult decisions during the battles against the Borg.
A really interesting plot could be a group of Space Marines who have been captured by the Borg. Instead of being assimilated immediately, they are used in some sort of experiment. One of the Marines manages to break free and starts to sabotage the Borg from within. He then has to find a way to communicate with the rest of his comrades outside and work together to defeat the Borg.
Here are some recommendations for novels similar to the marines:
1. "Refusing Qinghua's postgraduate studies, my liver became an officer." Author: Yuze Guardian
2. I'm Really Here to Maintain Peace. Author: Ghosts Never Get Lost
3. Film and Television Begins with the SEALs, by Little Soldier
4. " The life of an admiral from scratch."
5. " I'm a commander in the army."
6. "I'm a special forces soldier in the soldier assault."
These novels covered different types of Marine stories, including military, military life, and military science fiction. I hope these recommendations will meet your needs.