I'm not aware of any special insight that DeLucia has on Greenwood so that falls into the category of one person's opinion as far as I'm concerned.
As far as paying Greenwood "a lot of upfront money," his cap figure this year is $1.94 million which is less than what Foreman was scheduled to make this season. Greenwood's base is 540k this year.
Next year, Greenwood's cap figure (base + pro rata s/b only) is $3.85 and the year after that, it's $4.7 which is still significantly less than what Sharper made in '03 and '04.
Contrary to opinions on this board and elsewhere, I don't think it's a stretch to think that Greenwood can equal Sharper's performance on the field. Aside from one sequence I recall in the Raiders game was Sharper a big "playmaker" last season? He was involved in a lot of plays and piled up tackling numbers because that's what inside linebackers do in the 3-4. He was durable and consistent and to his credit, he put himself in the right position to make those tackles, but I don't think it's as out of the question as some people think to see Greenwood equal Sharper's "playmaking" ability.
Obviously at some point, whether it was the '03 opener or elsewhere, Capers and Co. saw something they really liked in Greenwood. I think what they see is a smart player - a hard worker, a good tackler and a good pursue and cover guy who consistently puts himself in the right position to make plays. If he's faster/quicker than Sharper, as we are hearing, then that's a bonus.
If the season were to start today, Wong would be at the Buc and Greenwood at the Mac, and Peek at the weakside outside. But, things can and do change.