Drawing on the bandwidth-fidelity principle (Cronbach & Glaser, 1957), this paper challenges the use of broad ImplicitLeadership Theories (ILTs) domains in predicting organizational outcomes (i.e., prototypic ILTs and anti-prototypicILTs) and provides preliminary arguments for examining ILTs narrow traits (e.g., sensitivity, intelligence) effects onLMX and consequently on work engagement. Specifically, using polynomial regression and response surfacemethodology, I examined the effects of followers’ ideal-actual ILTs congruence on LMX. Additionally, using the blockvariable approach, I tested the mediation effects of LMX on the relationship between ideal-actual ILTs congruence andwork engagement, on a sample of 68 employees. The results showed that followers’ fulfilled expectations aboutsensitivity and tyranny had linear effects on LMX, indicating the generalized benefits for leaders to be high on sensitivityand low on tyranny to enhance followers’ LMX. Intelligence, dedication, dynamism, and masculinity had non-lineareffects, revealing that fulfilling followers’ expectations are the best option for leaders to develop high-qualityrelationships with their followers. The mediation hypothesis received partly support, suggesting that additionalmechanisms can explain the relationship between followers’ ideal-actual ILTs congruence and work engagement.