What I remember hearing in Yeshiva 50 years ago was that the Alter of Slabodka encouraged short coats and fedora hats without beards to raise the self-image and pride of the Bocherim who were looked down on by the Baalei Batim as (ke-ilu) being old fashioned and consequently unable to find Shidduchim. A recently deceased American Rav told this story: that as a Bocher they went to pick up Zedaka boxes in homes 70 years ago and the old woman told him: “Here is my Zedaka box for the Jewish hospital so my children PUPU won”t ever need one, and here is my Zedaka box for the orphanage so my children PUPU won”t ever need one, and here is my Zedaka box for the Yeshiva so my children PUPU won”t ever go to one.” .. Pretty sad, but you have to thank Hashem how far we have come in the last 100 years. Anyway when the Slobodka Bocherim came to Jerusalem in 1924 the Yerushalmim were shocked and called them Muscovites and were happy to ship them off to Hebron. When they fled back to Jerusalem in 1929 after the massacre they couldn”t find Shidduchim until Rav Yosef Chaim Zonnenfeld broke the ice and took Rav Hirsch Kopshitz for his granddaughter.