Powell wasn't drafted by the Cavs and has a career average of 7.7 points in 18 minutes per game after six years.
Harris spent his first four years on the bench, never starting more than 14 games in a season until his fifth year. He's turned into a decent starting 2, averaging 14 ppg the last couple of years.
Daniel Gibson had a seven-year career in which he averaged 11 starts per year and 7.8 ppg. His specialty was spotting up at the 3-point line and getting passes from LeBron for open 3's. Without LeBron I'm not sure he even lasts seven years.
Danny Green was a great second round pick, becoming a regular starter halfway through his third season and having eight more seasons as a starter after that, averaging 8.9 ppg and 3.5 rebounds in 25 minutes per game. His career FG% is only 42.4%, however.
Boozer is the only Cavs' second round pick that came in and made an immediate impact and become a starter throughout his entire career, averaging 16.2 ppg. If I'm not mistaken, Boozer dropped to the top of the second round because he was fat and there were questions about his commitment to staying in shape. But he dropped the weight, got in shape, and started 54 games as a rookie. After two years the Cavs lost him to free agency when they tried to pull a salary cap shenanigan, releasing him under the mistaken impression that he would resign with them.
So in the 51-year history of the team I'm only seeing one second round pick that had any kind of impact in his first two years and only a couple that became productive starters a few years into their careers. I agree the best use of second round picks is to bundle them and move up into the first round for a high risk, high reward guy like Kevin Porter, Jr.
Reportedly the NBA is going back to allowing high school players to enter the draft next year which will mean there could be some diamonds in the rough available in the second round. Also college players that would normally go in the bottom half of the first round will be pushed into the second. Finally, the continued growth of the sport in other countries could mean there are better foreign players and more of them than there were previously so guys like Cedi who were taken with the second to last pick in Round 1 would now be available in Round 2.
So I'm willing to admit that second round picks in the future could be more valuable than they have been in the past.
Think you are forgetting Hot Rod