Well this is not good for the Admiral gang.
This shows Aramaki is definitely not top tier and simply being an admiral does not guarantee top tier status. Only confirmed ones are the original trio.
Getting heavily injured by a Boro breath is one of the worst feats in the manga when even Raizou could counter that.
No wonder the Revos could save Kuma.
So it looks like it is;
Akainu and Kizaru at top tier
Fuji - unknown
Aramaki as an in-between high tier and top tier