You can do some digging around on the Hodgdon data center. All the data you want, and it is free. You should find the some powders that are mentioned across the spectrum, but they won't be ideal for all.

Not too familiar with the .260, but it should like a medium speed powder like 760 as well.

My goal is to reduce the number of powders that I have. One should be able to get by with a quick one for light rifle, a medium one, and a magnum powder.

So you are looking at something like this:

Light rifle: H4895, varget, tac
Medium: W760, 4350, RL19
Magnum: H4831, H1000, Rl22

I gave you three examples in each catagory, but of course there are dozens that would fit in each. That is why simplifying is hard. Then they come out with something new like XMR 8208 and I suddenly need another powder.

You will find that a powder will cross over one but not two. For example, H4831 or RL22 will work in a magnum and a medium rifle like a .30-06 with heavy bullets. It may not be tops in both, but will work.

Similarly, Varget could work in .30-06 and in .223.

Note that what determines the powder burn rate that works best is the ratio of case volume to bore diameter. That is why the 7mm and .270 will be liking the same powders, though only one is called a magnum.

That said, all the cartridges you listed are in the medium to magnum range, so you probably can find something that will work well in all four. RL 19, H4831, RL17, Hybrid 100V, 4350.