The first of the lot was the Simmons... because I was really curious what I could do.
This head had been through the wringer. Killed a pile of Sage hens with it last fall and it spent it fair share of time skittering off through the sage and granite of western Wyoming. The edge was real rough, nicked and dull as my brain before caffeine.
The KME knife sharpening jig was used and I achieved a very sharp edge in short order... I'd shoot it at anything right now.
As suspected, the flat stones were working the grind with just the edges of the diamond hone making contact along the blade edge.
Although it worked well enough, I suspect that this process would cause excess wear on the edges of the diamond hone and would be even worse on a regular whet stone.
A rounded stone of some kind would be the ticket.