The Caves of Klydor by Douglas Hill, 1984.
This is the second book in a sci-fi series, the ColSec Trilogy.
The five remaining colonists on the planet Klydor have been exploring their new planet and trying to survive and to decide what they will do when the government department that exiled them to this planet, ColSec, sends its ship to check on their progress. Under Earth’s repressive government, dissents are sent into exile to become colonists on alien planets so that the government can later reap the benefits of anything they find or produce.
They get worried when a ship arrives on their planet earlier than expected. While searching for the ship to see who it is, the colonists encounter Bren Lathan, the best space explorer that works for ColSec. It’s his job to seek out new planets for ColSec to colonize. But, it turns out that he’s not there on an assignment for ColSec. He’s crash-landed on the planet, apparently frightened of pursuers, who may be the people in the space ship now on the planet.
Unfortunately, it turns out that Lathan is being hunted by CeeDees (Civil Defenders, the harsh law enforcement department that Earth’s government uses to keep the civilian population in line). Worst still, these ones are Crushers, a group known for using extreme force and not leaving survivors. They spot Cord and Samella, and they think that the two of them killed one of their people (who was actually killed by an alien creature). Cord and Samella manage to get awhile, stealing one of the CeeDee’s weapons.
Then, they discover that the reason that the CeeDees are after Lathan is that he is involved with a rebellion against the government of Earth, a rebellion that these colonists would very much like to join.
The themes of the story are still survival and teamwork. The colonists often have differing opinions about how to solve their problems, but they have to work them out because they only have each other to rely on. Lathan, who is much older than they are, doesn’t really respect them much at first or want to involve them in his plans, comes to realize that their skills and ideas are valuable and that they may be just the people he needs.