Jalima exactly, the David Suchet interpretation was close to this description, Poirot is a caricature in the books and that is how it should be when played on screen. Of course that description as open to interpretation, but Malkovitch doesn't provide us with an interpretation. He provides a provides a totally different caricature of his own making.
I think the script made the inspector quite gratuitously offensive in the way he spoke to Poirot, A man we are told he could only know by reputation and I think that even today, the way he spoke to Poirot would be considered unacceptable, in the general public civility of the 1930s it would have been considered completely beyond the pale.
Did you notice that to indicate the first victim was a slattern she is shown cutting a loaf. Its age being indicated by a green mould on the top, at least that is what it looked like, but in the 1930s, bread was all baked bread, it would have gone stale not mouldy. Only modern steam cooked bread goes mouldy.