I have been playing bass using the one finger per fret/ Jaco style of playing and have been making great progress. However I have been doing middle and ring finger isolation exercises and noticed that I tire and fatigue very quickly when using those fingers only. Over time, will those fingers ever get to a level of speed, endurance and coordination as the index finger? Same thing goes for the pinky as well. I notice that the big muscle along the bottom of my hand that controls the pinky tenses up pretty quickly and gets fatigued.