I have nothing against instructors using the name of a military unit to sell either their own hand-to-hand combat system or one that is used effectively by that unit. Not at all. For the most part, I see this as a marketing thing and each instructor/author has to make decisions on that front.
If you want to connect a USB device to an HDMI device then you must use a converter box. This is a set of electronics that change the protocols and signals. The only adaptor which works is the DVI-HDMI ones.
Most HDMI converters are devices that connect a non-HDMI source to an HDMI display. This means we're going from another signal type to HDMI. Some people get that backwards, but think of the signal as being something flowing from one location to another.