Z clauses...thinking about them from a different angle (part I the mischief)

I think I must be getting punch drunk not only on z clause discussions but on similar themes too. Many discussions are along these lines....

'We need to include a z clause for this particular bit of legislation.
Why?
Because we need to be seen to take it seriously (and of course they mean to take it seriously)
But how and why will a z clause saying you have to do what you have to do because statute says so make any difference at all in your contract?
Silence.
We just need to include this in our contract'

So in this line of questioning (where if you keep asking why you may just root out the mischief) we failed to discover the particular aspect of a piece of legislation for which there may not be a contractual remedy to run alongside some other remedy available to that party. If we could uncover that particular mischief then we can get our heads around the problem and decide a sensible way forward. Just randomly pointing to something in the hope everything will work out just fine is naïve at best.
So this note, part I, is about actually establishing the mischief you are trying to decide whether or not you need to contractually (or otherwise) address.