There are two kinds of Pecan. There are the Domesticated varieties from which we get edible Pecans and Wild Pecan that doesn't have much of nut. I don't know which one Franklin is referring to and I don't know whether Wild Pecan is stronger or milder than Hickory but everything I've seen before this referred to Pecan(Domesticated by my thinking since almost everyone talks about getting it from pruning and broken limbs) being milder than Hickory.
Another thing to consider. It's not everyday you see producing Pecan trees being cut down. I've seen Pecan groves in the same places with the same trees for 40-50+ years of my life. Haven't seen many of those trees cut down or even enough large branches come out of them to supply a hungry offset for very long. Wild Pecan is sounding more likely to me by the moment.