Yes they were armed, but when the consulate staff called Tripoli in a panic during the attack, the best Tripoli could do was round up SEVEN private security contractors, one of which was killed as you mention.
When you find more info on how many attackers died, please post. I think I read earlier that 8 attackers were killed, but that number seems very low. Mercenaries such as those contractors do not kill only eight unless only eight were attacking. I guess I can understand the number of real casualties getting out, but I always want to know everything. (maybe you posted that article. I can’t remember after reading so much today and watching college football all afternoon.)