1. The 5W may be up to an inch longer shaft, that may increase distance.
2. There are "hybrid" players and "fairway" players. Strictly individual.
3. Fairways have a larger face.
4. Hybrids have a tendency to pull shots - why some prefer driving irons.
5. The H is better with shallow/sweeping strokes than the HD. But so is the fairway.

You have both. When playing a par 5, take 2 shots for your second, one with each club. Pay attention to dispersion and roll-out as well as carry distance. You want to hit your 3rd from the fairway or land on the green without running off the back or sides.

That will tell you which you prefer.

The 5W will launch higher so will have better stopping power on the green ideally?
Also what would be better out of the rough, as that's more likely than hitting the 2nd shot from the fairway?

Hey man, its all about the yardage you are missing in your arsenal. thats what you need to think about when choosing a big set up. Look at your longest iron, looks like you said 4 iron, and figure out how far you carry that one in the air. And take the gap between that club and you 3 wood and calculate the yardage you need to hit in your game. Personally, I like hybrid clubs. They are so versatile and can be used in many situations!

Finally got out to play a par 72 course today where I could actually use my woods.
So it seems like I currently have no need for a 5W or Hybrid. As I was pretty consistently hitting my 5 iron 200 yds. And the times I hit my 3W it carried 230 as I was swinging slower so I could get better ball striking. I didn't have an opportunity to hit my 4 iron, but it seems it would fit right in that gap between my 5 iron and 3W. I did hit my hybrid off a tee on a hole that a pond was across the whole course. So you either had to hit it shorter than 230 or farther than 280 carry. So I hit my hybrid and chunked it pretty bad (luckily or it would have flown into the water for sure) and instead it landed 217 yards out.

210 yds was my 5 iron which is way left because I was playing the fade I always hit, and I hit it straight as an arrow...
237 yds was about where my 3W ended up off that tee, maybe a little further with the roll.
217 yds was the hybrid I chunked about 4 inches before the ball... but saved me from getting in the water.

Probably best to not worry so much about degrees of loft - instead focus on yardage gaps and pick clubs that can best fit the needs.

Some people hit hybrids better than irons or woods or driving irons, some do not - so let your capabilities and needs dictate what clubs makes it into your bag. This takes testing, trial and error, self reflection.