Cunningham hails from Division III program Marietta College, though he wasn't listen on its roster in 2023.
Horan was named Second Team All-Inter Ac his senior year.
Harris comes from Georgia with three years of eligibility remaining.
Olu Fashanu and Chop Robinson were consistently mentioned as first-round selections.
"This is my fourth time trying to establish an identity, trying to establish a culture. So everything is intentional."
The Steelers were McSorley's fifth NFL team.