Name that book

Rod Yonkauski

Possibly a Darkfriend
#1
Read decades ago.Group of American soldiers transported to a medieval kingdom,there to battle trolls,demons,goblins,the usual cast,trying to save the kingdom
 

Maark Abbott

Journeyed there and back again
#3
Read decades ago.Group of American soldiers transported to a medieval kingdom,there to battle trolls,demons,goblins,the usual cast,trying to save the kingdom
King Arthur and the Knights of Justice?