Hello earthdweller,
You asked: “why in dvihetuka the root mentioned only alobha and adosa without amoha”
Actually, dvihetuka is defined as alobha/amoha OR adosa/amoha.
– Amoha MUST be there.
That is because in order to understand Buddha Dhamma (to a basic level or to a deeper level) one must at least understand that one’s actions WILL HAVE consequences.
– That basic level of “wisdom” is needed for both dvihetuka and tihetuka.
Then to understand the deeper dhamma and get to magga phala, one must have a tihetuka birth with amoha/alobha/adosa.