These two phrases mean basically the same thing and indicate that there were so many dead bodies that the attackers piled them in heaps. (See: [[rc://en/ta/man/translate/figs-parallelism]])
The words "no end" are an exaggeration for the great number of bodies that the attackers piled into heaps. Alternate translation: "There are too many bodies to count" or "There are a great number of bodies" (See: [[rc://en/ta/man/translate/figs-hyperbole]])