I expect the Shinkos will replicate performance of the 203/204 combo. Consider them a street tire, but I have ridden them on the ranch roads of the Texas Hill Country, the service roads of the Ozark National Forest in Arkansas, and the loamy trails of the Blue Ridge Mountains in North Carolina. The pretty much suck in sand and mud.
I would not mix either the 203 or Shinko front with the TW34 rear off road. That is a recipe for severe washout and many faceplants from lowsides. That really sucks. Don't ask me how I know. On the other hand, tractionwise, the TW34 works as well as the TW204 on pavement and far exceeds the TW204 off road for a minor sacrifice in noise and vibration. Also, the TW34 will outlast the TW204 by 6000 to 8000 miles, and the cost is the same. It is the stock TW32 that is the culprit in ride discomfort.
For onroad, the TW203 is a good choice, even with the TW34 on the rear. That is the combination I ride on road, but I have a second wheel and brake pad set with a very aggressive Kenda Trakmaster K760 for for the dirt.
The Maxxis 6006 seems to be the best replacement dualsport tire overall, equal to the TW34 both on and off road. The Kenda K270 is a great choice for dualsport use, but the side rows of knobs are fairly soft and when pushed hard on the pavement the steering is a little squirrely. If you don't drag your pegs in the corners you probably won't have a problem with it. I've ridden the 5.10-18 size and expect the 4.00-18 size to be more heavily loaded and consequently even more squirrely. Granted, not many people have pushed a TW to its peg-scraping, knee-dragging limits on pavement, so I expect for most people the K270 would be a good performing tire even if somewhat short-lived due to its soft tread compound.
As far as I know, those K180s are not available in the U. S. of A. in the TW sizes. That's a shame, too, because they are a flat track tire with a soft compound for monster traction. It is commonly used for Tourist Trophy racing in Europe, kind of like motard racing in the U. S. of A. that combines roadracing, flattrack, and motocross style elements on the same track. Great fun.