Contradiction with 1 Chronicles 5:29-34
Lists the genealogy of the tribe of Levi, suggesting conflicts in tribe identity as Mordecai is from Benjamin.
Contradiction with Numbers 1:2-3
States the importance of knowing one's tribe for census, which can be seen as conflicting with Esther 2:5 if records differ.
Numbers 1:2-3: Take ye the sum of all the congregation of the children of Israel, after their families, by the house of their fathers, with the number of [their] names, every male by their polls;
Contradiction with Ezra 2:59-63
Discusses challenges of proving genealogy, which might contradict Mordecai's clearly stated lineage.
Ezra 2:59-63: And these [were] they which went up from Telmelah, Telharsa, Cherub, Addan, [and] Immer: but they could not shew their father's house, and their seed, whether they [were] of Israel: [Addan: also called, Addon] [seed: or, pedigree]