Simple builds ... like a simple heroes

Hi
Why for simple heroes dont exist assembly ?

Example : Slardar

blink \ stun \ ulti \ damage item like dagon ...

or Necro

blink \ Q \ VeilOfDiscord \ dagon \ ulti

for insta kills :)

In the past I played with Pugna and like it but neaw no more exist.

Sorry for my bad english.

maybe an opinion "ability#old"