I think this series has its tongue firmly in the cheek.
Hastings has become a parody of himself with 'bent coppers', 'mother of god' and 'fella'.
Arnott explaining the plot at each opprtunity.
Oh the whole thing is massively hammy and not to be taken seriously. If I took it seriously, I'd get very frustrated.
It's a theme park ride. Turn brain off and enjoy the ride I reckon.