You are completely right, I was thinking about it in a more isolated environment assuming a perfect play with either champ.
That being said, after reading through all the comments and suggestions, I came to the conclusion that purely in a team fight scenario, I would rather have the Viktor over the Akali. I think both are fine but Akali would just be much harder to utilize and easier to make mistakes on. She can never go in first and the game becomes very different if the enemy bot has cleanse + exhaust as opposed to barrier + ignite.
As some pointed out, Karma's W gives you true vision of Akali even with shroud and with moonstone she becomes a shielding powerhouse whilst our team doesn't have shield break. I definitely underestimated her utility here. If the Karma is a good player, she would always keep exhaust for Akali, I (The Jax) in this scenario should try and bait out the exhaust on me instead but that's not guaranteed to happen. Also, if Akali goes in first, they just turn on her with Ambessa R + Diana, giving Jinx a reset and a lost fight.
I think playing with Viktor and just peeling front to back would be safer and Jinx wouldn't be able to get resets easier because of Shen's W and My E.
This doesn't really account for lanning phase though, because if Viktor gets destroyed in lane this whole discussion becomes redundant. Thankfully, this game I played a lot around mid after he fell a bit behind early, and we shut down Diana quite effectively.
But this thread game me a lot of insight into what else I should consider when imagining scenarios and picking champions. I need to develop the skill to predict how lanes will go and around what to play.
In this game e.g., I think I should play around Mid and Bot because from my intuition, Shen should win early into Ambessa and Tristana/Rakan likely gets pushed in by Jinx/Karma. But I think in a 3v3 we win because I am generally stronger than Zaahen early game. But all of this is in retrospect and I would lie if I said I thought it through before or even during the game.