I'm 98% certain that that a red tiger Amakusa at the top, as said. Haven't tried a coarser stone like this as a fingerstone, but why not. It's not unusual at all to use equivalent sandpaper if needed. Amakusa are not valuable, and so if it doesn't work out no problem.
The second down looks like they're a few layers of aoto or, because they're a bit read, perhaps monzen (not really different from aoto). Does look like thirsty aoto, though. If I'm correct then the grit might be comfortable for kasumi polishing. However, the slurry might not be very abrasive (ie. fast). Aoto's aren't abrasive, which is why you sharpen along the layers, not on top of them.
Third down is green... No idea what that could be. Never seen a Japanese natural like that, so I'd say 99% it isn't.
Fourth could be from a finer, layered stone. It is hard to tell. Before anyone guesses Tsushima because of the colour, this would be unlikely because they're not layered and are crumbly so unlikely to be shaped into fingerstones. The colour is a little darker than dark finishers, and actually the texture look similar to the green.
Fifth - back of some kind of synth? The shrimp symbol is used by Chosera
Easy to play around with these, maybe on a practice knife, and see what they can do. I'm kind of doubtful how useful these are, though. Remember to thin them and give them the folds/creases to fit round the blade contours, of course. Technique is a little harder, but you could also take any natural slurry from full-sized stones and polish with that. (I just use some old, worn out sandpaper to rub with my finger. Fingerstones make me a bit impatient.)
