No im not crazy.
Itachi and Frieza are very similar plot-wise.
Itachi Killed off an entire people to stop a coup.
Frieza killed an entire people to stop a coup.
Itachi spared one of them.
Frieza spared one of them.
The one Uchiha that itachi spared, is the rival of the main character.
The one saiyan that Frieza spared, is the rival of the main Character.
Itachi died from an Uchiha.
Frieza died by a Saiyan.
I want to stress out that i am not comparing their personalities of character triats. Just the actions that they took and the similarities between their effect on the plot.