Around the end of the seventh season and the beginning of the eighth, two new players join our imaginary group, bringing it to the largest it well ever be: five players plus the GM. They're only occasional players, absent for many of the adventures, which the GM begins filling in with off-world science fiction, rather than the military-guarding-the-world that formed the basis of this new campaign. Nonetheless, both decide to play characters that mesh perfectly with the campaign concept, by designing members of UNIT.
The first, like the Brigadier's player, picks up a former NPC already associated with the campaign. Sergeant Benton first appeared (as a corporal) in The Invasion, back in the sixth season, and now returns as a semi-regular PC. As a sergeant, rather than an officer, he has the perfect opportunity to play the tough guy role previously filled by the likes of Ben and Steven. He doesn't really do much with the character beyond this, but it's a solid base.