After 22 re-rolls I settled on a Dry Rot with Solar, Field Choke, Full Auto, Smallbore, and Final Round. It's my new favorite shotgun to use in PvE. It's definitely worth grinding for and is better than I thought it could be to shred enemies. Plus it has a higher rate of fire, increased range, faster reload speed, and +1 magazine right out of the gate compared to the 4th Horseman.
That's a pretty great roll you got with the increased stability and with aggressive ballistics it brings the impact on par to a 4th Horseman. Range isn't a big deal since it's better to be up close anyway and I'd sacrifice that for increased stability. I'd probably keep it if I were you since it usually takes 15-20 rolls (at least for me anyway) before you get close to something you actually want. It took 11 rolls alone before Full Auto finally showed up for the first time.
An optimal roll for a legendary version of the 4th Horseman would be:
-Aggressive Ballistics
-Full Auto
-Reinforced Barrel/Smallbore
-Rodeo
Also, while leveling my Dry Rot through Dragon Strikes late last night I finally received a Hopscotch Pilgrim drop! It seriously only took ~100 strike runs for this to happen. Good grief.