You can have somebody that took 2 years to get all their certs that still doesn't know anything and somebody that might've took 90 days that is much more knowledgeable. You have to judge each individual well as an individual. I know me personally I strive to be the best so if I know I lack in a particular area I am going to study that much more harder and pick that many more brains. I have met guys that have been instructing for decades and I couldn't stand flying with them. I had an instructor that went to ATP (multiple actually) and they were a lot more enjoyable to fly with. One of the most knowledgeable instructors I ever flew with had 60,000 hours with about 40 or so were on floats. She definitely knew her way around an airplane.