What does get interesting is if you apply the "human" species to the bandit stat block. In particular, giving them an origin feat.
- Skilled? Perception and Stealth makes them marginally more dangerous, but has no effect on CR.
- Alert? Additional +2 initiative makes them considerably more dangerous, especially to 1st level parties, since if they go first 8 bandits could easily manage a TPK. However, initiative modifications do not affect CR.
- Magic Initiate? eight bandits, all casting Inflict Wounds on the 1st round, could wipe a 3rd level party of four. It probably boosts them to at least CR1.
- Savage Attacker? Was that a tumbleweed blowing past?