We find that adding D-sorbitol to PEDOT:PSS films improves the intermolecular arrangement of PEDOT oligomers, increasing the electronic coupling and decreasing the energy disorder in the amorphous film. We furthermore reveal that -despite its flexibility -PEDOT oligomers show a surprisingly low amount of static disorder which correlates well with its high charge carrier mobility. Combined with the high level of doping and, potentially, doping induced disorder compensation effects, these findings can help explain the exceptionally high conductivity of PEDOT:PSS.