Methods, devices and systems are provided for selecting one or more left ventricular multi-electrode pacing site(s). The methods, devices and systems measure arrival times of LV activation events for corresponding LV sensing sites, where the arrival times each correspond to a conduction time from an intrinsic ventricular event or delivery of a pacing pulse until sensing of the corresponding LV activation event. Site-to-site (STS) relative delays are calculated as differences between the arrival times associated with adjacent LV sensing sites. The STS relative delays represent STS arrival delays for corresponding combinations of the adjacent LV sensing sites. An LV electrode combination is identified that is associated with at least one of the STS relative delays that satisfy selection criteria, where the LV electrode combination corresponds to a target tissue region exhibiting a select degree of non-uniformity. The LV electrode combination is designated as a first LVEC pacing site from which to deliver LV pacing pulses.