I personally have "issues" with combined tail/brake and direction indicators in the same place. I have noticed in the past that they seem to cancel each other out (brain wise). I fitted flashing brake red leds into my rear indicator housings. But frankly I am not all that sure it actually gets me seen more.
There was a time when there had to be 4" twixt tail and indicator for this very reason. Based on my personal perception of seeing other folks rear lights: I think surface area matters more than intensity. I recall seeing a Victory Vision in the UK - very visible even a long way off but not killer bright close up. My mates Guzzi 1400 California is not bad either. Most cheap scooters have better tail lights than a Rocket!.