Sforno on Genesis 32:17/ספורנו על בראשית ל״ב:י״ז

1עדר עדר לבדו. In order for Esau to realise that each species of animals had the appropriate number of males with it to ensure that these herds would continue to develop without hindrance. This is what he meant when he urged Esau קח נא את ברכתי, “please accept my blessing” (33,11) He meant that his gift was designed to be an ongoing blessing for his brother.

2וריוח תשימו בין עדר לעדר, to prevent the animals form one herd to jump into the adjoining herd, so that anyone seeing this gift would not appreciate its quality and scope.