Sandy clay is a textural box on the soil triangle. It's small and requires the absence of silt. The reason we joke about them not existing is because of the size of the box and how far apart the two grain sizes are. There are very few scenarios where sand and clay would be deposited and not silt.
Imma be honest. I have tried my fucking hardest to learn this multiple times trying to roughly figure out what the best kind of foundation for stuff is and what I need to do to have better soil for vegitables, but it's impossible to do without hands on instruction.
It also doesn't help that topsoil where I am is often hummus due to leaf decomposition so it's hard to figure out if I actually have "loam" or it's something else, but also the fact that since I live on the side of a ridge you get like 3 types of "sand heavy" soil if you dig out a 4x4x2 box.
The high amount of humus you indicated makes things feel finer than they are. If you keep smearing or rubbing though it breaks down in your hand and you're left with nothing. Work with what is left over.
In general, SL to SiL is fine for veggies. CL even, but you have to be careful with watering.
LS is too coarse and you'll have trouble with water retention
Use this tool. Click the green button on the webpage, search up your location, on the toolbar click on the red square and draw a box around your yard, click soil map. On the left of the screen, you'll see a list of soil types on your property with their textures
The chart always looked wonky to me until I saw a version a former coworker had in his cubicle that put sand at the top instead of clay. For some reason the whole thing makes more sense that way to visualize the relationship clay has with silt and sand.
Just rotate the chart that was posted so sand is at the top and see if you see what I mean.
Also what's the deal with the weird shape of the Sandy Loam section? At the bottom center, there's a point where you could start with loam, then remove clay and add silt to get sandy loam. It has the same amount of sand!
Part of it has to do with loam being a balance of clay, sand, and silt but not equal parts of each. Another part of it has to do with the outsized weight clay content has on the soil characteristics.
This is also why loamy sand and sand are angled as they are in the chart.
So it is possible under some circumstances? I’ve actually wondered about this.
I guess it’s probably been created by people occasionally. I’ve had customers say they’re going to add sand when I tell them they have heavy clay. My colleagues always told me this won’t help but I’ve never investigated further.
The only references I can find for such soils are when there are highly stratified C horizons where a component may be sandy clays, like the Lohmiller series, at least that's my interpretation of the description