Shinzon and Picard's clone storyline was mundane.
Nah, but the storyline of Picard thinking he had a clone/offspring had also already been done
, and not that long before, in the TV series. "Bloodlines": The return of Daimon Bok ("The Battle"), trying to trick Picard into thinking he had a long lost son with Miranda Vigo.
Not to mention that Data having a brother was old news, too.