Maybe I'm seeing too far into puddles, but if we're trying to theorize the magic systematics, then I have come up with a theory. It'll probably contain spoilers simply because I am just trying to draw from as many sources as possible.
I'm sure that somewhere Brandon has confirmed or at least mention that, like in the Mistborn series, where the symbols stood for the different metals (and, coincidentally, while this doesn't quite correlate, had two systems in Pushing and Pulling), the glyphs that were on the front cover each stood for a Surgebinding, or perhaps just a system of magic.
He said that the top-right one (I think?) was the one we have already seen; Windrunning. I don't believe he clarified whether if this itself is a single magic system, or the two disciplines (as I will call them) of Basic and Full Lashings are each a system in their own right. As there were, as we know, Ten Orders of the KR, this would imply that the Windrunners operated just as single outlet of this kind. Implying that there are nine other sets of dual abilities? On this cord, we can safely assume that a Reverse Lashing is the discipline of a Stoneward? If so, what is the other one? This obvious suggests there are further uses for Surgebinding we do not know, as neither do Szeth, Teft or Kaladin (although he does not know of the Reverse Lashing, as he is surprised when he draws the Parshendi arrows to his shield, as is Teft).
This also leads onto the possibility that the glowing marks that Dalinar saw on the early Radiants in his visions could be this other ability of Stonewards. Or another ability. This then is clearly contradicted by the fact that one of the Radiants makes a jump that "is so much more that a Plate-assisted leap", probably half- or quarter-Lashing their weight upto leap further, which raises the question: Can the KR use abilities of other Orders? Then how can Kaladin do so?
I think it has been mentioned that one of the Orders handled Soulcasting, which must be one of two dual disciplines under a set Order title, of which I cannot speculate. Or perhaps there is just two abilities under Soulcasting. Clearly, the link to Shadesmar isn't coincidental, and so, in essence, I am going to theorize that accessing Shadesmar was the ability of this seperate Order, and that under that, within Shadesmar, there were two options: Soulcasting, that is changing the object's essence (or combination of essences), into another (combination, perhaps) of the Ten Essences, and Hoid's method to travelling the Shardworlds (and his pursuers, Seventeenth Shard, if his is the author of the Letter), which Brandon confirmed was linked to Shadesmar.
Also, moving onto the number of magic systems, there were said to be 30. Making assumptions, I will dole out 10 to each Shard(holder) currently present in Roshar as their direct influences. This is also, maybe, evidence to suggest that Ten is a special number in Roshar, like 16 in Scandrial.
Obviously, of the 10 they each hold, some will be variations of the other. However, this leaves a tangible confusion, with the KR possibly practicing what we think of as different magics, Soulcasting (Shadesmar Access, at least) and Surgebinding (maybe even Voidbinding, if you are so inclined about the KR). The following is my views on distributions of the magics:
Soulcasting: I am going to call Cultivation. I surprised myself with this one. But to me, at least it makes sense. Probably not to you. But isn't it the intent of Cultivation to grow? Then, isn't it reasonable that, rephrased, evolving one substance to another could be considered growth? However, the problems with this is whether or not Soulcasting could be classed as an independant Shard's domain. After all, how can ten other powers spring from Soulcasting to fill the quota (if there is one)? And then there is the question of it being included in the Orders (if it is) which would suggest it is a Surgebinding.
I will even go so far as to suggest that, as an access point to Shadesmar, the Cognitive Realm, then Soulcasting as Cultivation's domain implies that Cultivation resides over the Cognitive Realm. I would then place Honor over the Spiritual Realm, as his Shards (perhaps Splinters of Honor after Odium kills him) disappear to this Realm when not in use. That would imply Odium, bringer of Physical destruction, resides over the Physical Realm. This falls apart if Surgebinding though.
Voidbinding: Odium. In my opinion, however it is most likely to mix with the others at points. To little is known about it to make full assumptions.
Surgebinding: Honor. Again my opinion, but it makes sense. Following the Shards as Splinters theory, then it is entirely possible, if not likely, that the users of Surgebinding could wear or would wear these Splinters of the governing Shard of their power.
However, in line with a spren being responsible for all magics (or just Surgebinding, I'm not sure?) then this would suggest that the symbolspren related to Shadesmar Access would too be a part of the Surgebinding, like honorspren and bindspren, form a bond with certain people, aka Shallan and Jasnah, maybe even Dalinar and certainly Kaladin, in order to give them these base powers. Clearly associating Soulcasting with the Orders, and thus placing it under Surgebinding and Honor's domain.
Old Magic: In line with spren causing all change, and thus magic, I would assume this would make the Nightwatcher (sometimes described as a spren) the source for this. However, not sure whether to place it under Cultivation or not. Could fit, but this is a long enough post save that.
However, I do think that the Aimian man who collects notation on spren around the world, can't remember his name, could be very important to discovering or giving to us how all these magic systems work around one another.
Long post. Sorry.