Question: What type of a scholar was the rabbi who asked Rabbi Dovid Povarsky to join the previous two heads of the institute?

full_context: Document 1: Dovid Povarsky: Rabbi Dovid Povarsky (Hebrew: יהושע דוד פוברסקי‎ "Yehoshua Dovid Povarsky"; 1902–1999) is known for his erudite Talmudic lectures and his deanship as Rosh Yeshiva of Ponevezh Yeshiva. He was asked by Rabbi Yosef Shlomo Kahaneman to join the previous two heads of the institute, Rabbi Elazar Menachem Shach and Rabbi Shmuel Rozovsky to create a triumvirate in leading the Yeshiva.
Document 2: Menachem Mendel Schneerson: Menachem Mendel Schneerson (April 18, 1902 OS – June 12, 1994 / AM 11 Nissan 5662 - 3 Tammuz 5754), known to many as the Rebbe, was a Russian Empire-born American Orthodox Jewish rabbi, and the last Lubavitcher Rebbe. He is considered one of the most influential Jewish leaders of the 20th century.
Document 3: Conference of European Rabbis: The current president of the CER is the chief rabbi of Moscow, Pinchas Goldschmidt, who served as chairman of the Standing Committee for over ten years. The chairman of the Presidium is associate president Chief Rabbi Ephraim Mirvis. Before Rabbi Sitruk, the organization was headed by Rabbi Lord Dr Immanuel Jacobovits, Chief Rabbi of Great Britain. The Executive Director of the CER since inception was Rabbi Maurice (Moshe) Rose, succeeded in the year 2001 by Rabbi Aba Dunner, who passed away in 2011. In 2017 Mr. Gady Gronich, assumed the position of Chief of Staff to the President of CER and works alongside the Rabbinical Director Rabbi Moshe Lebel ,Secretary Rabbi Aharon Shmuel Baskin and President of Association and Special Adviser of the Board of Patrons Mrs. Shorena Mikava .
Document 4: Joshua Höschel ben Joseph: Joshua Höschel ben Joseph (died 16 August 1648) was a Polish rabbi born in Vilnius, Lithuania about 1578 and died in Cracow on August 16, 1648. In his boyhood, he journeyed to Przemyśl, Red Ruthenia, to study the Talmud under Rabbi Samuel ben Phoebus of Cracow. He returned to his native country, and continued his Talmudic studies in the city of Włodzimierz (Volodymyr, Volhynia) under Rabbi Joshua Falk. After his marriage to the daughter of Rabbi Samuel of Brest-Litovsk, he became rabbi of the city of Grodno, whence he was called to the rabbinate of Tiktin (Tykocin), and later to that of Przemyśl. In 1639 he became rabbi of Lemberg (Lviv, Ukraine) and in the following year he was appointed head of the yeshiva of Cracow. At Cracow Joshua devoted all his time to matters pertaining to the yeshiva, "din" (law), and religious decisions. As he was a man of wealth, he accepted no salary for the services he rendered to the Jewish community of Cracow.
Document 5: Chaim Potok: Chaim Potok (February 17, 1929 – July 23, 2002) was an American Jewish author and rabbi. Potok is most famous for his first book "The Chosen" (1967), which was listed on "The New York Times’" best seller list for 39 weeks and sold more than 3,400,000 copies.
Document 6: Elazar Shach: Elazar Menachem Man Shach (Hebrew: אלעזר מנחם מן שך‎ ) Elazar Shach (January 1, 1899 O.S. – November 2, 2001) was a leading Lithuanian-Jewish Haredi rabbi in Bnei Brak, Israel. He also served as one of three co-deans of the Ponevezh Yeshiva in Bnei Brak, along with Rabbis Shmuel Rozovsky and Dovid Povarsky.
Document 7: Joseph Lewinstein: Josef "Josek" Lewinsten (Lewinsztejn) was a Jewish rabbi and religious author born on July 11, 1842 at Lublin under the Russian Partition of Poland. He was a member of the family of rabbis and Talmudists which includes the author of "Pene Yehoshua" and the "Lebushim". Josek was the son of Rabbi Abram Abuś Lewinszteyn and Chana Lewensztein (Himmelfarb).
Document 8: Dovid Shlomo Novoseller: Rabbi Dovid Shlomo Novoseller, a descendant of Rabbi Levi Yitzchok of Berditchev (Kedushat Levi), Rabbi Samuel Eidels (Maharsha) and Rabbi Yechezkel Landau (Noda Biyehuda), was born in Yarmolintsky on Aug. 19, 1877, and received semicha from Rabbi Moshe Noson HaLevi Rubinstein, Av Beth Din of Vinnitsa.
Document 9: Yosef Shlomo Kahaneman: Yosef Shlomo Kahaneman (1886–1969), , was an Orthodox rabbi and rosh yeshiva of the Ponevezh Yeshiva. He was a renowned Torah and Talmudic scholar, a distinguished member of the Council of Torah Sages of Agudath Israel.
Document 10: Akiva Grunblatt: Akiva Grunblatt is an Orthodox rabbi who as co-rosh yeshiva (dean) heads the Yeshivas Rabbeinu Yisrael Meir HaKohen. (Yeshivas Chofetz Chaim) in Flushing, New York. (The other co-rosh yeshiva is Rabbi Dovid Harris.) Before being appointed to his current position in 2000, he was a rosh yeshiva at Yeshiva Toras Chaim in Miami, Florida.
Document 11: Sholom Rivkin: Rabbi Sholom Rivkin (6 June 1926 – 1 October 2011) was an Israeli-born American rabbi. He was the last Chief Rabbi of St. Louis, Missouri, and the last chief rabbi of one of only a few cities in the United States that has ever had a chief rabbi. He held the post of Chief Rabbi from 1983 until 2005 and was Chief Rabbi Emeritus until his death in 2011. He was also a chief judge on the Beth Din of the Rabbinical Council of America, and head of the Vaad Hoeir of St. Louis, the governing body of the St. Louis Orthodox Jewish community. He was an expert in Jewish law, especially family and divorce law, and was consulted by rabbis and rabbinical courts around the world.
Document 12: Yisroel Neuman: Yisroel Tzvi Neuman (born April 1947) is an Orthodox rabbi and one of the four roshei yeshiva (deans) of Beth Medrash Govoha (the Lakewood Yeshiva) in Lakewood, New Jersey. He shares this post with Rabbi Malkiel Kotler, Rabbi Yerucham Olshin, and Rabbi Dovid Schustal. He is married to the daughter of Rav Dov Schwartzman, who is a granddaughter of the founder of the yeshiva, Rabbi Aharon Kotler.
Document 13: Aharon of Karlin (I): Aaron ben Jacob Perlov of Karlin, known among the Ḥasidim as Rabbi Aaron the Great, or simply as the "Preacher" or "Censor"; born in 1736; died 1772. He was one of the early great rabbis of the sect who helped the rapid spread of Ḥasidism in eastern Europe, and was distinguished for the fiery eloquence of his exhortations. He died one year before his master, the great Rabbi Baer of Mezhirich, and was succeeded by his disciple, Rabbi Shlomo of Karlin. Rabbi Shlomo was in turn succeeded by Rabbi Aharon's son, Asher. Aaron is the author of the Sabbath hymn "" which begins and is still a part of the liturgy of the Ḥasidim. His ethical will and some collectanea are printed in the work of his grandson, Aaron ben Asher of Karlin.
Document 14: Hirsch Janow: Josef Hirsch Janow (1733 – 13 November 1785) was a Polish rabbi, who, on account of his great keenness in Talmudical discussions, was commonly called ""Hirsch Ḥarif"" (the acute). When in 1776 his father-in-law, Raphael Kohn, was elected rabbi of the 3 congregations Hamburg, Altona, and Wandsbeck, he succeeded him as rabbi of Posen. In the following year he was called to the rabbinate of Fürth. In 1779 he interdicted Moses Mendelssohn's German translation of the Pentateuch. Salomon Maimon, in his "Lebensgeschichte" (pp 280 et seq.), highly praises Hirsch Janow for his benevolence. He died at Fürth, Bavaria, on 13 November 1785.
Document 15: David Lau: David Baruch Lau (Hebrew: דוד לאו‎ ‎ ; born 13 January 1966) is the Ashkenazi Chief Rabbi of Israel achieving a majority of the vote on July 24, 2013. He previously served as the Chief Rabbi of Modi'in-Maccabim-Re'ut, Israel and as the Chief Rabbi of Shoham. Lau is the son of former Ashkenazi Chief Rabbi of Israel Rabbi Yisrael Meir Lau.
ground_truth: Torah and Talmudic scholar