One thing we learn when towing trailers for a living is load C/D/E ST tires simply will not stand up to this type of daily work for thousands of miles like a good recommended (tire mfg recommendations) LT tire.
Commercial grade all steel carcass 16" ST load G tires like the Sailun S637 are a class way above a poly carcass 16" ST load C/D/E.
The ST may have extra load capacity over the LT tire but it still doesn't have to pass the higher speed (mph) ratings of the LT tire.
Thats big for a lay person if miles (30k-50k) of trouble free service and reliability are expected from tires on any trailer.