You've presented what speculations and assumptions from characters in the game.
Speculation and/or assumption =/= facts.
And I find it very hypocritical that "I'm" ignoring evidence when you're clearly refusing to acknowledge what Lanius himself has to say.
I'm not ignoring your "evidence", I'm countering with that it ain't factual evidence but merely opinions and assumptions.
I'm not ignoring what Lanius has to say, not at all. But Lanius is not the only evidence their is to work with is he?
The Legion is Caesar, with the exception of House he's probably the smartest man in the game. This is made quite obvious through dialogue, yet you're quite willing to completely ignore what he has to say because you want to believe that Lanius isn't a psycho and he CAN lead the Legion after Caesars death.
Thats all this boils down to in the end. All of your supposition and opinions mean nothing because you didn't make the game, you only play it, like it or not.. Caesar doesn't trust Lanius as loyal, neither does Vulpes inculta. In fact its also stated in-game that the legion itseld doesn't like Lanius. Lanius lives for war and killing and there isn't any evidence in the game that would indicate Lanius wouldn't simply turn on the Legion once the military campaign was over. However their is plenty of evidence that he is a mental and he enjoys killing just a little too much..