It's an honest shame that Vic Morrow's voice was clearly dubbed by someone else in this film. It's like we only get half of Morrow's performance in this movie.
You've seen Guy Standeven in something because the man was in everything.

Or it could not have been part of his contract.
I heard the dubbing unions in Italy are incredibly strict.

Morrow was most likely unavailable due to scheduling as was often the case with American actors in Italian films. Often the films could afford to get them for a few days but not to have them come back for ADR. Morrow here was dubbed by Ed Mannix, best known as the English voice of Bud Spencer.