Ranks as disputes (4)
I believe the answer is:
rows
I believe this is a double definition.
'ranks' is the first definition.
(I've seen this before)
'disputes' is the second definition.
(row is a kind of dispute)
'as' is the link.
(Other definitions for rows that I've seen before include "Tiers" , "Banks" , "Columns" , "Rackets" , "Uses oars" .)