Well, considering what kind of structure his body is, you may not be surprised if Isayama's answer is Mikasa.
According to Isayama, among the 104 Training Corps cadets, Mikasa is the strongest. His physical strength is so great that it is unfair to cadets.
The second is Reiner Braun. This is also not surprising. Reiner is not the strongest for physical fighting, because technically it can be surpassed by Annie and the jotos she can be surpassed by Mikasa. (Although Mikasa and Reiner did not seem to have fought during the training, it was possible in the sparring ) session. But his body was built most firmly among all the other cadets. So for the panco, which relies on the upper body, it's no wonder he's the second strongest.
The third position was apparently held by two men: Jean and Eren. They are both winning, sometimes defeated, but consistently superior enough to occupy that position.
As for this intriguing fun question is one of the many fan proposed to Isayama from the official fan site, Mingeki . The author can not read the original question, of course. But there was a fan in Tumblr who kindly translated it to fan Attack on Titan all over the world can know anything asked to the mangaka.
So … in terms of physical strength Mikasa even able to surpass Titan Shifter . Indeed, he collided panco with human form Eren, but still it proves its strength. This question really wants to know the strongest Cadet Training 104 cadet. But I would not be surprised if Mikasa could win against an adult like Erwin.
What do you think about this revelation? Does this make Mikasa feel more macho? Convey in the comment field!
Source: Fuku-shuu tumblr