Salazar (atys)
I want to point out that Trytonists are neither atheists, nor pacifists, although they refuse the Kami as well as the Karavan. In fact, they take active part in the faction conflicts, as they have done in the past, when Elias Tryton called his followers to weapons during the Temple Wars: "So Tryton asked the homins to take part in the fight in order to maintain the balance of power ..." (Erlan Chronicles)
The main difference between the Marauders and the Trytonists, as far as I'm concerned, is that the Marauders in their slyness know exactly what they are doing, while the Trytonists in their delusion believe they know what they are doing. The Marauders decided to become villans for their own good, while the Trytonists think that killing homins of both fractions makes them heroes for the sake of all hominkind - which hardly makes them less villainous, if less predictable. The one (big, I admit) plus going for them is the deployment of the rainbow bridges.
Hey Salazar, actually, Trytonists have their own beliefs. They follow the will of Elias Tryton. In fine, their aim si to make sure hominity will live through and that, as long as there's no possibility to do otherwise, they will make sure no Power (K/K) is soing to takeover the planet. So basically, you can consider them a shadow player with an ulterior motive, which is to make sure that hominity will always survive.
Plus, true trytonists do not see themselves as Heroes for the sake of all hominkind. They always stay in the shadows, are nowhere and everywhere? They operate in secret and work to keep the peace on Atys.
On the other side, the Marauders did not decide to become villains for their own sake. They had no choice in that. They were the homins who stayed behind during The First Exodus. They ware abandoned by their own people. They survived by hating the homins who abandoned them and by killing each other off, so that they created an extremely violent Society. Basically, they come on Atys to destroy the nations. Their sole aim is to destroy homins, kill them off and make them disappear from Atys.
The marauders are no villain, they just want to destroy everything. In spirit, they're more alike terrorrists than anything else.
So comparing Trytonists with Marauders is so so wrong.
If you took care about what is happening in the different nations, you'd realise there are shadows forces working out to keep peace on Atys.
Plus, in the original version of the lore, the trytonists were meant to help the homins to become independent from the two powers, to liberate themselves and stop being slaves. The two times there was a great swarming, it was the Trytonists who saved hominity. That's all.
The Trytonists work for hominity, the Marauders just want to destroy hominity.
The Powers just use homins to sustain themselves.
Btw, each faction is a good choice to play in. Just don't say two groups with totally different aims are the same.