Shale drillers have an all-or-nothing reputation, with many pursuing growth at any cost. It's an approach that cost investors dearly during the recent oil market downturn, when many drilling stocks sharply sold off as profits plunged along with the price of oil. Their strategy was in stark contrast to the returns-focused one of big oil giants ExxonMobil (NYSE: XOM) and Chevron (NYSE: CVX), which preferred to balance growth with returning cash to investors by repurchasing shares and paying dividends.However, those big oil buybacks have now dried up, and they're falling behind their nimbler rivals, which seemed to learn the lesson that growing at all costs doesn't pay.