I see a repeat of the Hearns vs. Cuevas and Hearns vs. Duran. Certain styles were made to order for Tommy.
Armstrong was 5'5'' to 5'6'' face 1st swarmer with average to below average punching power for a welter. Against probably the hardest punching welter in history who was lightning fast with probably the best jab in the division history at 6'1''........ Due the math, Hearns by devastating early knock out.
Robinson insinuated he carried Armstrong. Don't read much into that fight. Hearns' physical advantages would simply be overwhelming for Armstrong. Just as it was for Duran, or Cuevas.
I think Hearns’ height, reach and power prevail here. Armstrong was a god among ATG’s and is p4p the better fighter. But he might be physically outmatched here