I fish 4 rods, two 8wts, a 9 and a 10, but I'll use lines from 8-12wt depending on the situation
One 8 is a 10 footer and is for surf fishing.... the extra length needed for mending over breakers when fishing in close.
The second 8 is the go-to. Light weight for all day use.
The 9wt rod gets used the least, but often it's the kayak rod.
The 10wt gets used mostly when the wind is up ... which can be fairly often around here.