Allow me to explain how Sans wields Swords and not Daggers as you suggest. If we look into Sans canonical height we can see he is 4 foot 5. A blade is typically considered a sword when it is at least 1 ft long. If we look at the official sprite you can obviously see that the blade is at least HALF his height meaning it's about 2 ft or longer meaning that the blades he wields are swords and NOT daggers regardless of what the Dusttrust team says is canon.