Romo's first offensive line was basically made up of 1st round rejects learning new positions. That O-line made more Pro Bowls than any other team during a six year period from 2003 to 2008
Leonard Davis was the 2nd overall pick in the 2001 draft. The Cardinals tried him at LT for his last three seasons there and they decided not to resign him. He was considered a bust and a terrible LT.
The Cowboys took him and turned him into the RG where he made the Pro Bowl for three consecutive seasons.
So he was considered a bust at his natural position but made the Pro Bowl his first season at a new position.
Marc Columbo was a 1st round draft pick in 2002, was considered a bust and started only 7 games in his first five seasons. He played LT.
The Cowboys took Columbo and made him their RT where he thrived. He played all 16 games in four of his next five seasons.
Andre Gurode, a Cowboys 2nd round pick, struggled at RG for three seasons. When they switched him to center he made five consecutive Pro Bowls.
A great O-line coach and/or coordinator will find the best 5 O-linemen and then fit them into positions that make the team more successful.