Farmer where I am clearing dead/dyiing locust showed my his pride. Planted 1892 by great great grandfather was 3 stemmed each of them going aroung 4' dbh. Almost totally dead from the borer but still putting out 'shoots' He had it topped due to hazard (house and power) but "I couldn't stand to remove it, my favorite tree since a kid".
I have never seen a big locust in a grove, lots of big isolated ones, or ones properly spaced growing as a fence line/windbreak. I suspect the groves of 'little' ones are due to thier copseing habit plus type of root. They do not have a taproot just roots spreading out in all directions. Thus competition in the grove keeps them small.
Harry K