A warren typically refers to the series of interconnected holes that rabbits dig and live in. Part of the defense they provide is the difficulty that predators like foxes have when navigating them.
In this instance warren maze just refers to a deliberately difficult to navigate floorplan.
It's not about saying it. It has to do with ordering it by size of time unit. Like I don't write the time as 43:12:19 to denote 43 minutes and 19 seconds past midday do I.