I’ll see what I can find.
Short Version:
St.Vith was a key road junction for the 6th SS Panzer Army advance. Between the Americans holding the Elsenborn Ridge and St. Vith the Germans had no where to go.
Due to the terrain in the Ardennes the Battle of the Bulge was as much a fight for roads and crossroads as anything else.
Bastonge was key to the 5th Panzer Army and the German failure to capture it in a timely manner meant the 5th Panzer Army abilty to maneuver was severely restricted.
Plus Bastonge had “Nuts” :-)
Regards
akfa6 ;>}