Adocs, Al pi Halacha, Yaakov Avinu did, in fact, do something wrong. There is a well known kashea is to the effect that, if the Avos were mekayem Kol haTorah Kuleh, how was Yaakov Avinu allowed to marry two sisters which is specifically forbidden. One answer I remember was the Avos were only mekayem kol hamitzvos in E”Y. Yaakov Avinu married two sisters in chutz la’aretz.
Also, in my and my parent’s generations, formal shadchanus as practiced today, was quite rare and confined, almost entirely, to the Chasiddishe Veldt. Most couples, including including those from rabbonishe (Litvish) families, met by introduction by friends and family or they met socially.