Hi there,

My advice would be to learn the Naniwas first before you start to mix 'em with your Welsh hones. I've never used a Dragon Tongue so I don't have any direct comparison but I find the Naniwas to work pretty fast on a razor with a well-set bevel so you probably need less strokes. One thing you have to keep an eye on though is that swarf builds up quite quickly on the Naniwas and needs to be removed regularly in order to make best use of them. To remove this the Naniwa nagura works nicely (a big red nagura that also comes with the Naniwa Choseras). I'd recommend getting on of these. However, Wet&dry should be fine to keep the Naniwas flat.

Good luck
Jörg

P.S. Once you get good shaves off the 8K I'd take it to the purple slate to see whether it improves the edge.