The same can be said for LEGO architecture. I like the 25° (AKA 33°) slopes as they are similar to a 6:12 roof pitch but the amount of parts is very lacking. We've got several widths of straight slopes, a hip (outside) slope, and a valley (inside) slope that is seriously lacking in color choices. There are also a couple of caps to finish off the ridge. But you can't intersect two ridges. Or run a ridge into a slope. Or cap a hip.
The 45° slopes are much more diverse. As well as several widths of straight slopes, there are enough auxiliary bits to make a respectable roof. You can do a true hip cap (think pyramid) or run a lower ridge into a roof slope or have a ridge that turns a 90° angle. My only beef with the 45° slopes is that this replicates a 12:12 roof pitch which is generally reserved for older homes, specifically Victorian or Tudor. The 12:12 is uncommon on newer homes. I guess that's just a good reason to do some classic homes with LEGO pieces, right?
Turns out, I've been working on a Micropolis scale Victorian home. I started with the roof to make sure that part would turn out right. There were four specific shapes I wanted to incorporate. The first was a hip roof overall. The second was to have an 'L' along the ridge. The third was to have a minor gable on one end. And the fourth, of course, was a turret or spire.
Here's my digital mockup which I'm quite pleased with. All my features are incorporated. I've noted the elements for you non-roofy type people. There are a few minor quirks in the design but it's otherwise straightforward. I started by sketching out the basic hip shape before adding the gable end. That required 2 piece swaps to turn that portion of the slope vertical. Rather than mess around with the next level up, I capped the gable end with a 3049. This is a 1x2 double slope (ridge) with a little pointy inverted portion on it. The pointy bit is specifically designed to sit flush over slopes.
On the back side I ran into a temporary issue with the ridge turning the corner. There used to be a piece (called 962 in Ldraw) that was made specifically for this application. However it was last made in 1969. For a buck I could have a used one. But I don't want a red or blue roof. There are no other options. I'm guessing that this part was discontinued due to it's uselessness. There's nothing it could do that two other pieces couldn't achieve. While it's always nice to have variety in pieces, sometimes the purple area of the Venn diagram is not cooperation but redundancy.
In my case the solution was easy. One ridge was built as usual with the triple slope hip piece 3048. Then the other ridge started by capping the first ridge with a 3049. Both ridges were finished with the same triple slope. From a house building perspective, this looks like tack-on to me. But I guess when building with LEGO pieces, strict structural rules are not always necessary.
But one issue remained. I needed a notch for the turret/spire/rocket ship to fit through. For this, I could not find an extant solution. There are some parts that come close. The 3045 would be the part that would normally fit. But I need that corner gone. There's a newer 13548 that is somewhat faceted but it still does not eliminate the corner entirely. Best bet is a 1x2 slope in one direction and fake the other side with a cheese slope.
Instead, I decided that something MUST be done about this gap in the canon. A new piece was in order. But much like the forgotten ridge corner, there's no use creating a piece that only has a very specific application. So we need to take an existing piece and make a mate that will not only fulfill my needs but many others as well.