36 Thirdly, even if I had formed a contrary view and concluded that some discount from each of the maximum sentences imposed was appropriate because of the early plea of guilty, before the appeal could be allowed on that ground, it would have to be established that the sentences imposed were excessive (Criminal Appeals Act 2004 (WA) s 8(1)(iii)). In the present case, the effective head sentence imposed by the Magistrate was a sentence of 2 years imprisonment. As I have observed, he arrived at that period after applying the totality principle, having regard to a maximum available term of 4 years and 3 months. An effective head sentence of 2 years could have been arrived at in a variety of ways; for example, by imposing sentences of 9 months imprisonment on each of the 2 counts of driving whilst under the influence, cumulative upon each other, and also imposing sentences of 9 months imprisonment on each of the counts whilst driving under suspension, but making those sentences concurrent with each of the offences of driving under the influence, and then imposing a term of 3 months imprisonment for breach of bail, cumulative upon the other sentences. Given that the breach of bail was a separate event which occurred some days after the first driving offences, such an approach would have been entirely consistent with principle and a proper exercise of the sentencing discretion. The result of such a group of sentences would have been identical to the sentences in fact imposed. Rearranging the sentences in this way on appeal would only have been "tinkering" contrary to established principle - see, for example, Dinsdale v The Queen [2000] HCA 54; (2000) 202 CLR 321 at 340 - 341.