Why didn’t Levi inject both Armin and Erwin? Levi decided to inject Armin with the Titan serum to have transform the almost dead Armin into a Titan so he can consume Bertholdt to gain his Colossal Titan Abilties


Why doesn’t Levi just inject both Armin and Erwin with half of the serum each so both survive?
I cant remember if anyone, Levi included, actualy saw when he tasted the serum, did they? And either way, there was one guarantee to get one of them into action, or a chance to get both, but if it didnt work for any reason, everyone would get ripped apart or eaten alive. I watched the show, so could have missed some info from the manga, but sounds like good reasoning to me.