I think you'll be alright, so long as your barbs aren't massive and the cories aren't fry-size.
Did you get C Habrosus or C Pygmaeus? Habrosus are true dwarf cories. They're kind of goldish and have black blotches down their sides, as well as having very rounded heads for cories. Pygmaeus are pygmy cories, who are silver with one black stripe down each side and a normal-shaped head. Pygmies tend to be more of a midwater fish when given a large school, dwarves usually stay on the bottom.