So indy stock work for you, that's cool. But they don't work for everyone or Indy wouldn't make Aftermarkets. Stock thunders don't work for me (94du do). AF1 low bushings (in AF1 lows) don't work for my, I needed to buy the hards.
No truck requires you to buy an accessory before you ride them. I know two dudes that skate stock royals, no issues.
The stock royal bushings are amazing but not if you ride tight trucks / weigh more than 150lbs, they're very soft. They'd be fine but I can't stomach threads showing, this isn't the fucking 80s; that goes for every truck =D What I found odd is they never firmed up, they break in and just....continue to break in =D
Indy blues worked great in royals but soooo many threads showing.
I tried Venture cast and immediately dipped (after a week, skating 2hrs+ everyday); the royals provide the stability of Ventures but turn better; hell the pics I posted comparing the two trucks clearly shows royals are modeled after Venture.