He built a fortune lending to low-income borrowers shunned by banks. He paid staff below-market wages and thought they still earned too much. He gave away almost all his wealth to a handful of employees, content with his small house and a $5,000 car.R Thyagarajan is arguably one of the world’s most idiosyncratic financiers — in no small part because his multibillion-dollar business, the Shriram Group, has thrived in an industry that tripped up countless others around the globe.A pioneer in extending credit to India’s poor for trucks,...