Isso é respondido no Stack Overflow:
Qual é a diferença entre - geral as opções -numeric-sort e --numeric-sort no gnu sort
Da resposta:
General numeric sort compares the numbers as floats, this allows scientific notation eg 1.234E10 but is slower and subject to rounding error (1.2345678 could come after 1.2345679), numeric sort is just a regular alphabetic sort that knows 10 comes after 1.
Do manual de classificação do GNU :
Use [general numeric sort] only if there is no alternative; it is much slower than --numeric-sort (-n) and it can lose information when converting to floating point.