I disagree with you here. I don't think that Parker ever played for us as a real out and out holding midfielder. He was primarily defensive minded but still had license to get forward when sensible, Modric would then drop in to cover (as I would imagine instructed by the manager and as is sensible). Harry's Spurs team was fantastic to watch. We played brilliant, attacking football, generally always taking the game to the opposition. That was the way that we played because we had a bunch of excellent attacking footballers. However if you think back to our away game in Milan, Redknapp also showed that he could set up a team to defend deep and play purely on the counter.
First half a season Parker played almost exclusively in our half, didnt venture upfield, didnt try any ambitious passes or runs. He sat in front of the defence and went after anything that crossed that halfway line like a rabid Jack Russell. And in this capacity he was magnificent, and in turn allowed the whole team to play freely. The like of Modric working wonders in the middle 3rd, Walker/Rose/Ekotto bombing ahead etc.
That version of Parker didnt last too long though, and after than half a season or so he started thinking he really should be more like Steven Gerrard. And in doing so he fudged the balance of the side, and compromised players far superior to him like Modric.
This was a team with no predetermined strategy, shape, ethic - call it what you will. As Scara said, Rednapp was all about letting players play their game.
He did on a few occasions actively manage more, Inter as you say. Though in a similar vein Arsenal always spring to mind first. In those early encounters with them Redknapp(? - Bond maybe?) very specifically had the team sit narrow and deep, allow them the ball anywhere in their half or wide (they were brick from wide positions) and then hit them on the break. Worked a treat.
Those occasions were very much the exception though, and not the rule.
This isnt me trying to slag Redknapp off, its just his tenure as I saw it. Some good football, from some great players, and some fantastic times. But, ultimately, a sense of frustration at a lack of development over time.
As I said, I think he reached his limit, the club didnt, and by the time he went (for whatever reason) it was about right that he go.