Think about it. They were building up Deanne to be a total psycho in the best (worst?) Kimberly Shaw manner but clearly, she didn't make the cut. Episode three and Rachel Dennis enters and Deanne says buh-bye.
I don't think Rachel replaced Deanne in terms of character traits but I do imagine Kim Raver was dropped to make way for Rachel as there was only so much room on the canvas (and money in the pot). In terms of Deanne becoming C.P.W's Kimberly, I think they considered themselves more sophisticated than MP and said at the time that they'd be staying away from having a resident psycho or random explosions. Of course, this approach went out the window when they decided to turn Alex and Mark crazy.
