In your last ask you compared Reiner being offered help by Bert with that panel of Armin lending a hand to Eren when leaving the Reiss Chapel, but I'm pretty sure Isayama's intention was to make it similar to that instance Eren saved Armin from the bullies at the start of the story, or the time Armin was reminiscing about Eren being strong and saving him many times when he thought Eren died in the Battle of Trost. In that case, Reiner would be "the Armin".
Artistically I think the two panels I shared were strikingly similar, thus the “can I copy your homework reference”, but I agree thematically the connections between the Shiganshina trio and Warrior trio aren’t as clearly defined.
There are times in the flashback where Reiner was “the Armin” of the group, but throughout the chapter Isayama was trying to draw the strongest comparison between Reiner and Eren. @etoincognito captured many of those references in her excellent chapter write up.
We’ve been talking for years about how each of the trios (vets, warrior, and shiganshina) have similarities. In each group there is a heart, a mind, and a body. Hannes is the one who defined the Shiganshina trio this way, and it seems to follow with the other trios as well.
This chapter made it abundantly clear that Reiner is the heart (or spirit) of his trio. He’s the one who believes most ardently that his cause is right, his vision motivates the others, and he is thus the most emotionally impacted by it. Leviskinnyjeans wrote about this two years ago. Despite all the new information, the post holds up well.
Here’s the panel from Chapter 1 that I think you are referring to. It is similar as well, although Armin refuses Eren’s assistance.