I would argue probably not.
I'm in a similar position to you, I have a 4, 4.5, 5, 5.5 & 7. My 5.5 is kind of redundant for general hand tool work (I make furniture out of salvaged pine with predominantly hand tools), the No.5 is my workhorse, and I find the 5.5 is a bit too wide to serve as a...