Well that sounds like self-defense a bit, yes many die but they would of all been indoctrinated and essentially dead I assume anyway? Unless they were indoctrinated anyway, or indoctrination can be broken, or would they have been killed?
The difference with Solas was well for one he was already a part of the Evanuris, he was basically a member of this slave-holding titan-killing machine and just kind of went snitch on them.
But Solas wasn't one of the Evanuris, he was Mythal's guardian. There is absolutely nothing in the game to suggest Solas ever did anything like what the Evanuris did - notice how there are no Fen'Harel Vallaslin. Even if you look at the legends about that time, there's no mention of it. (and remember that the legends are actually all propaganda against him in the first place)
The legends about Fen'Harel at the time of the Evanuris only talk about -
- he saved a village of children. The adults die to a beast, but this is because he was not strong enough to fight it head on.
- he "hunted" Halla from Andruil without permission - and it seems pretty likely these "halla" were actually a metaphor for elves he was recruiting/rescuing since Andruil hunted them.
And then there are Cole quotes that seem to refer to him that talk about how he didn't even want to come to this world because he didn't want to fight.
Seriously, there is nothing to suggest he has anything like what the Evanuris did.
I take it you also think Mythal is a psychopath?