Yes, they are right
So, I think I get it, “le + VN” is not relative but locally points to the intended action, “lena” links a tool and the intended action relatively to the target.
Tá deora ag carnadh i mo shúile arís,
tá fiche buicéad móra uaim lena mbailiú, (the tears)
fiche cailín gleoite deasa lena n-iompar, (the buckets)
fiche clais doimhne lena n-adhlacahd. (the buckets or their contents, not the girls I think)