Sheim mi’shmuel explains [not on this specific question] that the people Yaakov hinted to are those who had middos that reflected on yaakov’s own hcildren.
Efraim is yehoishua, efraim learnt by yaakov, while yehoishua was the ultimate tlamud of moishe, compared to the moon which receives light.
Shimshon was don, acheiving great things even when all looks hopeless, chushim, me’asef lekol hamachanois, etc…
Dovid and Yehuda are malchus. {see ramban as to sho’ul)
One can suggest that yaakov gabe the direct brocha to levi, that of ??? ?????? ????? which obviously includes moishe