One of my expensive sets came with two 3/4s and no 19mm.

I went back to the shop and said no. They said ok. Fucking A.
If you mean the 1/2 drive fit varies then definitely NO. Just no, China.
A good 3/4 drive set is $ but you'll like having it if you're working on anything of size.
Also there's so much fuckery with torque numbers on rattle guns and drills that their claimed specifications are basically meaningless. Don't buy Horror Fright shit, man. Get real tools. Buy once, cry once. On the up side, if it hits like a girl then you don't have to feel so bad about not using proper impact sockets, right?
Prepare your nuts, Johnny. Oil and heat before you crank the 6 foot cheater bar with a jack and beat on it with the sledge.