Is it enough to recite every day the invocatory verse (thaniyan) of a Samasraya Acarya or should we recite that Acaryan’s Acarya thaniyan as well?

We must recite our Acarya thaniyan and his Acarya thanian as well. The preceptors would have preached about the recitation.
We need to worship the entire lineage of Preceptors (Guruparampara) as per the preaching of the respective preceptors and in the order that it has to be recited. The scriptures say that each Acaryan must be worshipped by individually reciting their names or thaniyan.