I have a couple of Triumph rods, the 8ft 4pc 4wt and the 7'6" 2pc 6wt (one of my favorite bluegill rods) and both work well with a line size smaller. I have tried the 9ft 5,6 and 9wt and they work with one size lighter line. They are all very forgiving rods to cast. I expect the same would apply to the 7'6" 4wt, though if you are going to be making mostly short casts, you may prefer a 4wt line.

I saw the sale on those an am tempted to pick up a half dozen Triumph rods in various weights to have around as loaners.