Comparing 2 deeps, I used the 2 deep roster for both teams from the Ourlads website. They actually show more than 2 players for some positions so to be consistent I only recorded the class for the top 2 players and I didn't include special teams since that didn't seem to be the question. So here's the comparison of the 2 deeps.
Penn St
SR - 11
JR - 14
SO - 10
FR - 7
Pitt
SR - 17
JR -,9
SO - 14
FR - 4
So once again Pitt had more seniors on the 2 deep (17 to 11), but the amount of upperclassmen was nearly the same with a 26 to 25 edge to Pitt.
Obviously Penn St had the edge in SO/FR in the 2 deep (19-18), but that was buoyed by 8 Lion freshman that made the 2 deep to Pitt's 4. Penn St lists 2 Redshirt Freshman as starters (one each OL/DL). Pitt listed none.
Digging a little deeper into team experience, consider how many starters (not 2 deep but players listed as the starter) have been in a D1 program for 3 or more years (JR, RS JR, SR, RS SR)? Penn St starts 17 players and Pitt starts 16 with JR eligibility or higher. Pitt is also a little more top heavy as more of those players are seniors. Conversely, Pitt starts 6 underclassmen (SO/FR) while Penn St starts 5.
There are some points of disparity but it is a little more balanced than I would have expected.