Steel choice also depends a lot on what the knives will actually be used for. ESEE makes outdoor/survival/hard use knives.
So ZDP189 is probably the wrong choice. 1095 is a very proven steel for harder use, and simple to sharpen, which is important, since few of us drag a belt grinder and 10 miles of extension cord into the woods.
I don't think they could do much better than 1095 at the price point and I don't think their knives would benefit a lot from "better" steel.
Besides, Rowen arguably produces the best 1095 in a production knife and then some.
The final question is: what steel should they use to be worth the money in your opinion, OP ?