Use of star wiring as described is not a unanimous agreement. When my son gave me a DCS set the week it came out some 20 years ago, I plopped the TIU between transformer and track and have been running ever since (much expanded). I have 12-gauge bus running around the layout for ground, and 14-gauge wire runs from the 72 toggle switches on my control panel out to individual blocks. It was designed that way in the early 90s to permit multiple locos to be run conventionally. The late Marty Fitzhenry also did not use star wiring.