I prefer multiple rods. Its just because I am a little lazy. I don't want to take the time to change out a lure when I am on the water. My inventory wasn't built in one day though. Start out with the necessities and add to it every now and then if you feel that isn't enough. I agree with jbcarroll3000, its not about right way wrong way, its about preference.
I roll similar to SAKS. It has taken me about 10 years to build the lineup I have now that consists of about 20-25 or so rods with only a few that are the same. For me it is about having the right feel for the particular bait.
I use a different rod for different size rouges. Same with 4 inch swim bait as compared to a 7 inch. 1/4 oz trap and 3/4 oz trap on different rods. 1/8 oz bullet weight vs. a 1/2 oz. Line size used is also a factor.
And so on.....
Granted that I don't catch a lot of fish these days but man am I ready when I go.