Della Valle averaged 4 points in his sophomore year. Could he have been a contributing factor? Sure, but likely not. He was shooting 32% from 3, and he was supposed to be a 3 point specialist.
Sibert left because he was going to be on a team with Aaron Craft, Q Ross, Shannon Scott, Lenzelle Smith, Deshaun Thomas, and Sam THompson fighting for PT. He was the worst of those players going into 2012-2013, so he left.
JD Weatherspoon averaged 3 points his sophomore year, and was academically ineligible for the 2nd half of his freshman year. He would've been fighting with Sibert and the other guys, who were better than he was. WHile he was successful at Toledo, it is unlikely he would've had any impact at OSU.
Offutt only played in garbage time at OSU, and was benched for a few games. Maybe you could argue he was a miss.
Zisis - NO. (Played professionally in Greece, has topped at 6.6 points and 4.7 rebounds per game. He was TERRIBLE.)
PJ Hill GRADUATED FROM OSU. He topped out at 12 minutes a game in Evan Turner's player of the year season, playing alongside Buford, Diebler, Lighty, and Dallas Lauderdale. Whose time was Thad going to take away?
Eric Wallace played 3 seasons at 3 schools (OSU, DePaul, and Seattle).
If you want to give Thad crap about bench usage, these are NOT the players to use. Especially Hill, Wallace, Zisis, Della Valle, and Weatherspoon.