Anyone who examines the dead soldiers’ armor and ★succeeds on a DC 12 Intelligence (History) check recognizes them as★Knights of Solamnia. (Artanis has advantage on the check).
When you search the remains, you find correspondence that states the knights were investigating reports of nearby farmsteads being raided by strange creatures that match the monsters’ descriptions.
Conclusion
Shortly after the monsters are defeated, Rhys rejoins you and asks them what those monsters were. He has no idea, and you don’t either: this is one of the first times monsters have made their way into Solamnia.
It’s not long afterward that more travelers come along, joining you and whomever you were traveling with towards Vogler.
As for the cart, it need merely be righted. It was, fortunately only toppled over, and not destroyed or broken.