I see.
Without overreaching, I think its fair to say that the Chaco War would only interest those into interwar infantry heavy clashes. It does have a certain imagination quality to it and is 'different', sitting squarely between WW1 and WW2. I think one of its main attractions as a 'side period' is that the buy in is pretty small. A couple of platoons and you're done. You can use most terrain from any other period from WW1 and WW2 and it's not building intensive or anything like that. Really the most you 'd need would be some entrenchment, a few out buildings, etc...In some respects it is close to jungle warfare in WW2 and more open clashes as well as the terrain did definitely vary in density and type.
Tactically, its appeal is the interaction of changing infantry quality and organisations as the war progresses and off course the conflict itself...it’s a contained conflict with lots of scenario opportunities without having to 'make stuff up'.
Cavalry...well, yes at the scale of CoC there is most definitely cavalry present...you can have a whole mounted platoon. In theatre most cavalry fought dismounted due to issues of massed cavalry forces and limited water supply but there were always mounted elements for rapid movement so cavalry it certainly has...and should have.
..one could mount a Beersheba type ' get to the water' cavalry charge if you were so inclined!
Bottom line is it has all the moving parts of a typical CoC game with armies, doctrine, tactics and the familiar suite of support weapons...all the WW2 stuff...it just has less 'sexy kit'...but frankly, in most CoC games there is usually only one or two of those anyway.

PS..speaking of infantry and SCW (well, it is my thread)...I had a very nice line of Asaltos go at some Regulares just a few days ago...not a tank in sight!
...now that is an infantry line
