"Saupers Companie" isn't correct Dutch, that should say "Sapeurs Compagnie". I've heard and read every possible explanation. Dutch KNIL, Belgian Colonial, Danish, French
Foreign Legion...
I'm not saying that my French SAU theory is correct, it's just a theory as I have clearly stated. But the French Sections Adminstratives Urbaines in Algeria is the only (para)military unit that uses the SAU abreviation.