Well, the difficulty is that cases, even complex cases, vary so much in their circumstances, in the kinds of issues—charter issues or evidentiary issues or whatever issues—they might raise that there is no predictability in the abstract for saying how long a complex case would take.
That said, the point you've made is that complex matters can take, in some cases, years to make their way through the courts after charges are laid, and I would have to agree with you that this is indeed a reality.