The best case for Payaguá relatedness is with Guaycurú and/or Guachi
Viegas Barros, José Pedro 2004 but the parallels are still insufficient.
Payagua, a poorly attested extinct language isolate of Paraguay, is missing from
E16/E17/E18/E19 ( Lafone Quevedo, Samuel A. 1910 , Peña, Enrique 1898 ,
Boggiani, Guido 1900 , Charles B. Mansfield 1856 ,
Schmidt, Max 1949 , Parodi, Domingo 1880 ).