For reference, the caravan encounters were created based on the benchmarks in Table 1-1: Monster Statistics by CR on p. 291 in the Bestiary. However, as has been pointed out, those CRs were based on the operating principle of a PC party, with 4 PCs vs. one opponent. However, the mistake that we made, apparent in retrospect, is that the caravan isn't 4 PCs; it's *ONE* PC. As a result, those target CR benchmarks ended up 4 CR's too high.
Is it perhaps the same just make the caravan level = highest player level + 4 from the start (so starting the caravan at level = 5), and leave the encounter stats unchanged? Or, since the level just determines how many feats a caravan has, just start with 4 more feats and pretend that a first level caravan has 5 feats?
Could it introduce other problems?