The three Gundam mecha are entirely fanmade, though the third's chest portion is based on the Deathscythe and the first's on the Exia.
The second of the Destroids (all non-transformables in Macross and non-humanoid non-transformables in Robotech) is indeed called the Monster in both series, while the first Destroid is called the Raidar-X in Robotech and the Defender in Macross, and the final Destroid is called the Excalibur in Robotech and the Tomahawk in Macross.
The second of the Destroids (all non-transformables in Macross and non-humanoid non-transformables in Robotech) is indeed called the Monster in both series, while the first Destroid is called the Raidar-X in Robotech and the Defender in Macross, and the final Destroid is called the Excalibur in Robotech and the Tomahawk in Macross.