First level fighters in breastplate and shield = hard as hell to hit. That AC 17 means that, even with a STR 18, a level 1 character still needs to roll at least a 12 to hit.
It sounds like the NPC warriors had the advantage over the PC's. Three fighters at level 1 = ECL 3, which means (by definition of ECL) that a party of four 3rd-level characters should be sufficient to challenge the enemies.
* Was the R/Ro alone, skulking about pointman-like, or were the PC's together when the attack happened?
* Did you give the R/Ro a Spot/Listen check to see if he would notice the oncoming murderer?
* Did the R/Ro realize he was outmatched and attempt to surrender/retreat/fall back to his allies?
* Did the R/Ro have an opportunity to try other combat tricks, like disarm, or grappling? (Risky business at 1st level, but better to try and die than do nothing and die)
Barring that, why couldn't the PC's rescue him, or 'bind his wounds'? Why did the NPC have to kill to PC?
All questions to consider, imo.
