In The Kite Runner, General Taheri is a complex character who is, in the final analysis, fairly sympathetic and benevolent, a good father and a generous father-in-law. His greatest flaw is his pride, the excesses of which would not have been revealed if he had not fallen on hard times as an immigrant.
The most similar character to General Taheri in The Thorn Birds is Archbishop (later Cardinal) Vittorio di Contini-Verchese. The main difference is that the Cardinal never has to relinquish his high position, so the reader never knows if he would have reacted as the general did. He shares General Taheri's benevolence and his active mentorship of the next generation. The polar opposite of the general in The Thorn Birds is the stingy, malevolent Luke O'Neill, who has neither benevolence nor the sense of dignity and propriety that underlie Taheri's pride.
In A Thousand Splendid Suns, it is difficult to find a clear parallel for General Taheri. He is somewhere between Hakim, a devoted father who lacks Taheri's personal pride, and Jalil, who reflects the general's pride in his high status but is not such a good father. Since Jalil regrets his failure to be a proper father to Mariam and the reader eventually learns the depth of his feelings, which he hides effectively, he is probably the closest to Taheri. The polar opposite of Taheri is Rasheed, who experiences a similar fall in status to Taheri's but reacts quite differently, unraveling and becoming a brute.