Ethan and Lana both took an arm of Bachus to help, considering the rest of their squad was busy further up and they really weren't needed there. Bachus did need the, even if he denies it, they both knew different. Also, secretly Ethan particularly wanted to be apart of Levi's squad. Who didn't!? Sure, being in the scout regiment was an honour something to be proud of as it stood, but the Levi squad was legendary. 

So the twins figured if they could help that squad out, it was as good as being a part of his squad for the time being. Lifting Bachus up they shared his weight. "Neisha, let's get Bachus back ASAP. We can find something to stop the bleeding on the way!" Lana suggested.