QUOTE
Imagine you are in front of your radar screen controlling some 30 aircrafts (just about). Suddenly, 5 more aircrafts pop up on the screen but you have no time to listen to what they have to say nor look at their levels/headings. You then decide to give them random FLs and headings hoping they will not crash into each other nor into the other aircrafts.
UNQUOTE
I can think of more than one trainee I have seen over the years who seemed to take that approach! They didn't last very long!
P.S. Plural of aircraft=aircraft