The Alphas have as much chance of being used in combat as the Grob Tutors used by UAS/AEF, which are also on the civ register. Geneva Convention not really an issue.
The Chipmunks and Bulldogs used before the Grobs used to have a (rather controversial) war role during the Cold War. I suspect the Grobs are still pencilled in to do something useful if the balloon goes up in a big way.
Alpha jets are actually fairly useful light ground attack and COIN aircraft, which was the role specified and exploited by the Luftwaffe. They're phenomenally agile and precise. I'd expect they'd get called up before the Grobs
Absolutely delightful plane to fly though. Delightful almost glider-like purity of handling combined with instant, smooth, linear power on demand.