When I enlisted, the Army had just begun to develop & institute "Army Combatives" across the board, as instructors started to filter out of the combat arms schools and into support branches. That system is mainly a rebranded BJJ, with some judo & TKD strikes for added spice.
This time-period was also during the run-up to the '03 Iraq invasion, and there was a lot of training cross-pollination between coalition troops waiting to go over the berm from Kuwait.
That was when we also had a good amount of downtime between training ranges, and queued with a detachment of Ukrainian troops; who had with them the guy who helped develop the Ukrainian hand-to-hand doctine, which is essentially Systema & Krav Maga.
Our own unit training NCOIC also happened to be one of the guys fresh from the infantry's Combatives instructor course, so guess what we did, instead of gas-mask training?
They routinely kicked our asses, until we started implementing elements of their repertoire.
That was enough for me to keep up with it, until I picked up my DD214. Since then, victims to practice moves on have become rather scarce.
Although I do still have a scarecrow/jousting-tree in back that I use for buttstroke & bayonet training.