I think the line reflects water, tactics and your preference.
I would note Kelly G has done much to promote streamer fishing for trout, especially with BIG flies, but he has expressed views that are NOT DH, so his comments reflect his SH and large fly preference, and strip in the fly.
So I have 4+ rods that I will use for Trout and Streamers where I would be using "spey" techniques. Starting from my short rod .
Don Anderson Bamboo 8' 5wt with an old Cortland 333 Double Taper
(showing its age, but it is better than the new 333 or 444). Vertsatile and great for pocket water or when I am expecting a hatch. A goto streamer in a deep pocket would be a conehead muddler (pulled out some surprises this way!) or spiders.
I could also add in a size 8 scuplzilla, If conditions change, I might put on a Klinkhamer and a small nypmh, or a dry fly.
This rod Bamboo is a great roll caster, and thus well suited to SH Spey setups, and not just overhead casting. I am storing my lines on a Hardy Princess. I am not a believer on superlight reels on trout rods, not against them, but I keep most of the trout setup on the Princess, so it is easy to change things.
The forgotten older Scott 10' 7wt ARC 4 piece is a great SH spey rod. I have landed Atlantic Salmon, Steelhead and Trout on it. It is great after a rain and you are fishing from a bank. My wife (and fishing partner) often picks this as her rod, after the rain to work the bank.
I have an old and discontinue Airflo Multi-Piece line with Sink Tips. I think the closest available now is the RIO Scandi Short VersiTip
. It is on a Loop 2W (now Danielsson) reel.
My backup is a James Green 10' 7 wt Fiberglass with a 360 grain (a little heavy) Airflo Switch Streamer, and I have used OPST Micro Command Tips
ACR 11'7wt - smaller wet flies, spiders, smaller. I believe I have a 240 grain RIO Scandi Short
on a Hardy St Aiden Reel. I either have a hand-tied leader out of Maxima or a 8' furled leader with mud to help get the leader down. I rely on the weight of the fly.
I am not expecting to go deep, I am working runs, pocket water, et cetera.
Meiser 12'6' wt 4pc with a SGS 324 Grain at 31' with RIO Versileader.
Flies may be weighted. I am not expecting to strip a lot, and having the extra sink on the fly at the opposing bend of the river may be important. This line is on an older Nautilus CCF 10 (8 would be better), and sample flies would be scupzilla, bunny tube or a large mouse.
and I do keep some conehead muddlers or even a thick squirrel nymph to downsize.
Many words and images, but what I am suggesting there are many options, and select in accordance to your water and how you like to fish. The detailed description is to get an idea of the tool setup I use depending on the conditions and what I want to achieve. There is no need to add as many rods, et cetera, but I enjoying trying new water, new methods, et cetera.
If I am walking in, or hiking up a stream for the day, for trout, I am likely to carry two rods, almost always the Meiser 1264 and often the Anderson Bamboo 5wt to do a major change up. As my backpack can carry more, I am likely to add more.
I also will use two other tools, I really like the recently discontinued Scott Meridan and will use this to throw long and strip in flies, such as on an estuary. I have some 8wt RIO
Coastal and Airflo 40+ sinking heads (long heads). I also use this rod for Bass, Pike and Bonefish.
And when I am travelling, I will have a Meiser 13' 5wt 5 piece. I also have some Guideline and 3M UST 3D heads, ranging up to 6 sink (a beast to get up and setup for a cast), but it is great if I want to go deep.
There is no reason to not keep it simple, but just illustrating there are different tools and reasons for them.