This gets....complicated.
Part of the complication comes from so much of the material I can find being written about spanish dirks or colonial knives coming from historians whose specialty lies elsewhere. What we know as a spanish dirk or the most direct descendants- the gaucho knives- seems to have been called a mediterranean dirk, peasant knife, I've even seen references to the pattern being of nore northern western european use.
Certainly there is a moorish influence, but finding details that are reliable is hard.
Several things about the general pattern have always appealed to me. I like the single edge design, the versatile blade profile, and the edge drop of the style. With or without a guard proper, it's a very handy knife for general use as well as flesh poking.
I've been wanting to make a more military knife for a while now. While a couple of leuku pattern blades have gone to the sandbox, I've wanted to do something that has the proper feel for a combat knife if need be. But I agree, and generally don't see why people outside of certain specialties would be best served by a pure combat knife that's not really useful in general.
The field dirk is where I'm going with my own personal answer to that. I'm still sorting out the handle specifics, as I said. I also need to deal with the blade itself. I'm partial to something with a rather full distal taper, going from 3/16 down to near nothing all along the length of the blade. I would prefer to keep a convex grind, but can see doinga scandi variant at some point. I doubt I'll get sucked into serrations, or anything really weird.