Jumper cables unsuitable for recent diesel engine

RAS on the product packaging and delivery: perfect.
Problem: lack of specific technical information on site and on Amazon to the product label itself other than "cable designed for large vehicles and Cable section of 5.65 mm2."
Unfortunately, it is with a similar diameter cable that I did not start a diesel vehicle type 308 with 2 different vehicles last weekend. I had to spend a licensed store who told me that this type of cable was inadequate to start the recent diesel engine. By analogy with the one I have already in my possession, I deduced that the copper section of 16 mm2 is probably largely inadequate (see information on the internet). It takes a section of copper cable (not the outer sheath) 35 mm2 to ensure sufficient power transfer.
This jumper is therefore inefficient to boot recent diesel engine.