If I don't do brown rice, is it okay just to feed the carrots, broccoli and maybe kale along with the meat, and extra vitamins, or should I add another filler?
It would depend on the purpose of the "filler."
I think you mean a source of calories that are cheaper than the ones from meat, fat, or other vegetables.
Because you do not need the "right" texture to make kibble, and you are not trying to make the cheapest-possible dog food, you probably just need to get the right amount of calories for the dog from other sources.
(I do not know dog nutrition well enough to recommend what to feed, but I understand part of the purpose of grains in a commercial dry dog food--texture, and cheap calories.)