The overkill is referring to the weight of the car, BOT add how many kg weight, the more weight u pack the more braking power u need. Tell your myvi friend to jam the brake at 160km/h n c he can control or even survive to tell u..? All the weight is infront, when u jam brake, your rear will float if u on stock suspension even with ABS, bcos your rear grip has less braking distribution due to the front grip even more now. U need very hard front spring so that it won't dive down. If u have equal upgrade to the back say front 4 rear 2 then its another story.
Ordinary for R32 who weight 1 n a half ton, how many swift weight..? a ton... With racing pad its a cheap track weapon, not any ordinary brake, a single pot is ordinary brake.
Im using evo twinpot on corolla, car heavier then your swift, but its enough to stop the car where ever i want, then its sufficient. I always drive my stock single pot n rotor to purple colour, i wan to try better braking power, that y i upgrade to twinpot. Choosing the right brake pad is very important comparing big brake. I can jam my brake n activate the ABS anytime.
Not saying its no good or anything if u upgrade the rear brake n suspention setup, its just safer without all those spacer...