Why are people comparing Calpernia with Samson as though one has to be better than the other?
They come from the same basic context and are moved by similar motivations: ensure their people survive the mage-templar war.
Calpernia is as bad as Samson in the sense that she reduces herself to be Corypheus's mindless tool in the end (to become his Vessel).
And as much as people criticize Samson for leading the templars to their doom with red lyrium, we can scarcely imagine what Calpernia ordered the mages to do in the name of Corypheus - probably submit to the Venatori, who'd force demonic possession in them to gain their obedience - because we never actually SEE IT.
Calpernia seems to be this clever nemesis who didn't take a stupid decision towards her people (such as Samson did) because the players have NO IDEA what was the fate of mages other than to side with the Venatori. The only clue you have as to what became to either side of the war is if you side with the mages. You KNOW for sure that Samson's choices were lame because you get to JUDGE HIM. You get to hear his confession. And then you learn that feeding templars with red lyrium was a choice based on loose criteria. Samson could have made better choices, but no. He went with the lamest.
But do you get to hear what Calpernia did to the mages? Do you hear her justify the crimes she commited - and which we never hear of, anyway - and how did she make the choice to side with Corypehus? NO.
So people speculate she is a cleverer nemesis, a much worthier foe because in ONE cutscene AND ONLY ONE, her motivations sound much more solid.
I mean, what the hell is this line of thinking? Didn't Calpernia make the rebel mages side with the Venatori? Didn't Fiona make the same mistake before Calpernia by siding with Alexius? Who honestly believes the mages are now better off under her leadership than the Red Templars under Samson? We don't know what the Venatori made them do. We don't know if they are forced into ritualistic sacrifices to summon demons. They're probably all enslaved and being forced to use blood magic to carry their orders.
I don't see how that's better than what Samson did to his people. It's as demoralizing and as desperate a measure as the one he made. Calpernia and Samson's decision-making processes were the same. She knew trusting Corypheus was a poor idea. This was the guy who opened the Veil and brought darkspawn and the taint to the world. This was the guy who sacrificed thousands of slaves, like she once was, to do that. Hell, he would've sacrificed her if she had been in Tevinter fourteen hundred years ago. And she is fully aware of that. How can siding with him be such a grand idea?
The same goes for Samson. He knows red lyrium destroyed Meredith. And yet, he embraces it, under the illusion of Corypheus's promise of power.
One villain made decisions as lame as the other did. There's no better or worse villain. They're two sides of the same coin.