No...
KT is about a single squad-level of models. I guess what I mean is, that there are a lot of Kill Teams where two boxes of models is enough to make a "full roster" team with lots of options to substitute.
For example, a Box of Tactical Marines and a Box of Scouts makes an excellent Kill Team. A box of Tyranid Warriors and a Box of Termagants makes a great kill team. A box of Ork Boyz and a box of Gretchin... if you don't mind some konvertin' of the Boyz, makes a good Kill Team.
If you get bored with painting one faction for too long, you can always paint up a Kill Team to break the monotony... and then have a "complete" army for the game.
I was through with 8th edition, but wound up collecting
KT's for Nids, Necrons, Tau, Grey Knights, Orks, Marines (using existing stuff I had) and Guard (using stuff I had).
My boys (11 and 9) like to play now and again, so we have lots of variety and it was great for me because I could try new things, paint a unit of stuff I wouldn't necessarily want to build an army out of. Great for the hobby Attention Deficit.
Which of course lead me to expand the collection of Tau into a proper army... you know how it goes.
(
PS: I'm liking 9th so far, but I also liked early 8th...)