After the Brian Schmitz Orlando Sentinel article appeared with the quote from Magic GM Otis Smith, stating that he might not sign another big man AND the ensuing comment thread here at OPP regarding that article, I decided to take a look at the numbers. 

How are the Magic doing during the times Dwight is on the bench since the big trades?

The Data:

(All info taken from basketball-reference.com team unit data through Jan 10, 2011)

• The table below shows all lineups without Dwight since the trade with greater than one minute of floor time (of the nine other units with < 1 min, there is only one score for Orlando and one score for the opponent in 4.13 total minutes; so it just becomes statistical noise).
• Even the units that get below 10 minutes of playing time are difficult to use in drawing conclusions (so don't make too much of a particular lineup that has very few minutes).
• Some of these lineups are garbage time and likewise difficult to use in drawing conclusions.

[click table to enlarge image]

Update #2 (10:25pm EST) new table. Thanks to an inquiry by Matt1325, I realized that my original method of calculating the difference between ORtg and DRtg was not correct.  In the new table below, I've summed and calculated the ORtg and DRtg based on the possession and point totals, rather than my original method of trying to produce the results based on weighting each lineup according to its % of total minutes.

Some concluding thoughts:

There is a reason Allen, Duhon, Q. Richardson are not in the regular rotation.  Their units tend to be the statistically worst.

Weighting each lineup for its percentage of total minutes, the Magic ORtg/DRtg differential is +16.07 with Dwight off the floor since the trades.  [Update #2: This means that without Dwight, the Magic's ORtg is 16.07 points better than their DRtg.  This is not the same as an on/off rating....in other words, the Magic are not 16.07 points better with Dwight off the floor than with him on the floor.  Or vice versa. Nor is this a simple +/- rating.]

So far, so good.

Certainly an injury to a rotation player would be a concern (as it is for any team in the league). Even then, the Magic may have the personnel to weather the storm.  For now, it appears that Otis' "if the right deal comes along" approach continues to be the correct one.

Update #1: Copying my comment from below into the post itself:

When Malik Allen plays center, all of the 5-man units with negative ratings come with Duhon on the floor (looking at the whole season).

Allen + any other PG = positive-rated 5-man unit. (Well, perhaps there is one exception to note. One of the negative units has Duhon and Nelson in at the same time with Redick at the SF versus Philly—the game when the trade was going down—so it is hard to tell who was the PG and who the SG…or really for that matter to use that game as much of a measuring stick at all.)

However, Allen + Duhon is not always negative. Sometimes that combo has positive rated 5-man units, too.

I was just surprised that Allen + any of the PGs besides Duhon seemed to do okay in limited minutes.

Btw, Allen at PF never seems to work very well either offensively or defensively. One more tidbit: Allen has zero minutes with Clark.

So, really an injury to any of Howard, Anderson, or Bass could significantly hurt the Magic, and would push Turkoglu and/or Clark into more minutes at PF.

Data on Allen from: http://basketballvalue.com/player.php?year=2010-2011&id=130