1)
Are these Efrayim's sons in Bamidbar 26:35?
1.
Radak #1: Yes - Shuselach is like there, Bered is Becher 1 , and Tachas is Tachan. Malbim - this opinion holds that the Torah omitted Efrayim's other sons mentioned here.
2.
Radak #2: No - all mentioned after Shuselach are sons of Shuselach. Malbim - it is as if it says v'Gomer after Bnei Efrayim Shuselach. Bered Bno, Tachas Bno? all mean Ben Shuselach. Here discusses Bnei Shuselach, but not Efrayim's other sons, for Yehoshua comes from Shuselach.
1
Malbim: It is difficult to change a name so much. Also, Anshei Gas killed them (21). The Torah says that they were Roshei Mishpechos! It is difficult to say that only those after Tachas were killed.
