Where do you disagree, Roy, and think I will be weak on offense?
I think Fisher, Pietrus, and Thomas as all weak offensive players. Also, I don't think it's a given that Gasol is going to improve his production like you and Who are projecting. Right now in Memphis, he draws the other team's weaker big man, because defenses need to match up with Zach Randolph (along with Mayo and Gay, as you've pointed out). When defenses now only have to key on stopping Gasol + Kobe, I think Gasol's numbers will either stay level, or decline slightly. You and Who are basically projecting Pau Gasol production for Marc, and I don't think that's realistic.
Thus, I think your offense is going to be almost entirely reliant upon Kobe, a player who showed noticeable signs of decline last year (although he's still obviously an elite player). On a lot of nights, I think opposing teams will outscore your starters head-to-head, and defensively, your bench won't be able to stop anybody to make up that gap.
In the end, I just don't think that Kobe + Marc Gasol + a bunch of below average players (and Pietrus, Fisher, and Thomas are all well below average at their positions) is good enough to place higher than third in this division.