The experience of courts shows that attempts to make Acts of Parliament totally comprehensive with no room for differences in interpretation have failed. Trying to cover every eventuality does not work, and is not necessary when courts have a measure of discretion. This means the argument that clarity should be sacrificed in an attempt to be comprehensive does not stand up. Laws were originally written in Latin or French, and many of the common terms are still being used. Drafters were once paid by the word, rather than by the job.
Drafters rely on precedents, using ancient clauses rather than 'risk' using original language.
Many old documents which are now part of our law were written by humble court clerks rather than skilled lawyers. This may be because of a tradition of making each part of a bill only one sentence long. Experience shows that shorter sentences, each dealing with only one main point, are more effective. This does not have to mean a 'Janet and John' writing style, rather a conscious effort to make each sentence serve one precise purpose. As well as obscuring the message, this can be legally dangerous.