Again, & I'm sure I sound like a big fat broken record after all these years, but the Bujinkan is chock-full of useful techniques, specifically in the jujutsu schools. The problem is in how they are trained, if they are trained at all. The general sloppy training methodology of 99% of the Bujinkan is it's greatest downfall & the main reason I've not trained Booj in almost a decade.
Just my 2 cents ( & if anyone has been filling their piggy bank, it's probably full by now).
It looked like an honest attempt at light randori at first, but by the middle/end they were clearly trading techniques, not resisting, holding the arm out there and letting their partner go to work while they politely hold still. Nothing wrong with going light, but you have to be free to move/react for it to be sparring imo. I'm glad you guys are trying to play with your techniques in sparring in any case.
At least they're trying within the Buj parameters. I went to a Buj club many many years ago that had bare knuckle sparring (no head shots) and MMA style grappling. The instructor had an elevated Bujinkan grade and aside from a few of the kata pretty much everything he thought his really his own style (a mix of kick boxing and wado ryu with lashings of ninja imagery). So even though it sounded like a hard hitting Buj club, it wasn't really Buj at all. If the training in the OP's vid was promoted in Japan there might be some hope for the Buj but it's not, so the best you'll get are guys like this experimenting and trying to make dodgy techniques work without any proven instruction or instructor to back up their efforts.
RRWAA: For the purposes of training, have you ever considered buying a Redman/High Gear suit (or just assembling your own from various bits of gear)? One of them can help you try out the more dangerous theoretical techniques your art teaches without having to compromise movement (for the most part) or safety.