Every time an American claims our mecha are more realistic because they're walking tanks with gun arms, we're usually talking about something copied from stuff like Macross because it got repackaged to us as Robotech and Battletech.
They're all built on the AT-ST from Star Wars... but if it's got gun arms, torsos shaped like modern military vehicles, and thrusters, that's a blueprint Japan put together and popularized. It's just funny that we keep insisting there's a distinction or that it belongs to us after decades of messy lawsuits.