personally i think they should add these:

Hiruzen sarutobi(young adult), Minato(sage mode), Sasuke(Curse mark lv1), Sound 4 curse mark, hayate gekko (edo), Suguru aburame(i have no clue how well known he is but hes the ninja that poisoned shisui so danzo can have his eye), and Omoi(KIba). I also think raiga(the seven mist swordsman)should be added