Interesting thread, explanations and links, thanks!
I still struggle to understand how matrix games really work; but I'll probably not understand fully till I try one.

I like the idea that it's not competitive, and is somewhat RPG.
When you've been playing wargames for 30 years like me, you might think that you've pretty much seen it all. Turn-based, IGO-UGO, alternate turns, reaction systems
Argad ruleset has simultaneous moves by mutual agreement.

(perhaps that's why it's never been very popular)
