This may help a little more.
In its upright most position, the long arm and adapter is 1.5" taller than the bandai. The short arm is half the length of the long arm so it should be 2" shorter than the bandai arm. If your 19 fits with the bandai stand and has 1.5" clearance, you should be good. Keep in mind you could shorten the long arm by tilting it back/forward. A single short arm is probably too short for battroid, unless you are giving it a pretty wide stance, or walking/running pose.