stofsk, it's clear from the tenor of Traveller (no matter the edition) that NPCs are JUST LIKE THE PCs. They have careers; they have skills; some of them are psionic (even scary_psionic); and many carry guns and wear armor.
Searching the rules for specifics....you can look at Appendix I: Friends and Enemies from The Traveller's Handbook.
Those bandit/guerrillas do have lower stats than an average PC, but they have +5 ranged (assault rifle 1d12/x2) attacks. They've got the basic feats for rogues + mercenaries and their technology level. I'd say they definately are full-fledged characters and therefore a threat, potentially a dire one if a firefight with automatic weapons breaks out.
The high tech guards ALL have V/grav, AP/light+medium+vacc suit, WP/armsman+marksman+combat rifleman and several useful feats. They have 3 levels of professional, which weakens them in combat somewhat, but that choice might get made by a player, too.
Even the functionary (that poor victim) has Driving or Pilot +9 and either V/wheeled or V/grav depending on tech level. Admittedly, he's got no weapon proficiencies, so his attacks are very weak, but even with -3 on his body pistol, he hits a AC16 opponent 10% of the time.
No, I have to disagree with you, stofsk, the rules as written DO actually say the NPCs are just like the PCs. And they're almost as dangerous. I say almost because PCs have mean 12.5 stats while the NPCs have 10.5, but with guns and Lifeblood that isn't as much of a difference as many might like.