Maritime work song tradition is measurably older than the English (chanty) + French (chanson) languages laid end-to-end.

And there are more allowances, and synonyms, for 'sailor' than one can count. American cotton screwers were land based unions working alongshore. G. E. Clark's and Charles Nordhoff's chantymen wouldn't meet the dictionary definition of chanty. Neither would T.W. Higginson's gospel singing, U.S.A. infantry oarsmen.

U.S. and Royal Navy fiddle, fife & drum instrumentals or Catholic vespers as capstan cadences would not be a 'qualitative' step backward on any scientific or practical level. Both are older than, and coexisted with, the chanty era.

The usage of the chanty genre label and the practical application of nautical work song have entirely different critical attributes and sorting criteria.