[quote=@The Mighty Hero]
[@Cardamonelaw] Perhaps instead of your character sitting out he alternatively tries to find out more information from the town folk and can end up meeting up with the other players further along this quest? If that's something you would be interested in to keep you active in the RP and to give your character a chance to get loot/XP along with the other characters PM me and we can work it out.
[/quote]

If sitting things out is a genuine inconvenience as @JBRam2002 worries, honestly, almost ANYTHING in-character (and not a thought bubble) tipping the balance in favor of Alric not seeming like he's full of crap would probably be sufficient to have Arius turn around. Like even ONE, just ONE other villager randomly noting something like, "I heard Alric is trying to get our friends back.", indicating that Alric is not lying and people have in fact been taken would do it.   

The main problem for Arius is that his background makes him disinclined to engage insurrection/rebellion because he's a noble from a family stalwartly loyal to the Crown. He doesn't like his family's allegiances and is ethically at odds with them, but he still honors their position when possible. He's only begrudgingly pro-King, but he's still pro-King nonetheless (he's LN as opposed to straight-up LG for a reason). So when a random stranger calls for insurrection against the local political figure, based on an unsupported allegation that said politician has done wrong, he's reluctant to participate but willing to give it a look based solely on the severity of the allegation. But then when all the facts observable in-game indicate said random stranger is a liar... well, it would be really out-of-character for him to keep going along with things, even with Ada's alternative motivations.

I honestly didn't even think this would be a serious issue, as the game recruitment seemed to imply the individual character positions on being for or against the King/current regime were an anticipated/planned for dynamic element of the game. When a DM makes a game where individual players can choose for their characters to be either Team Red or Team Blue and has the very first in-game quest be Assault a Red Team Base, I'm inclined to assume they are anticipating that Red Team-affiliated PCs probably aren't simply going to go along with that and are prepared to work around it.    

I'm certainly not trying to be rude/insensitive toward either the DM or my fellow players.