Since there is a thread for the manga, why not have one for the mecha considering that there are quite a few differences when compared to the animated UC.
Like how the Guncannons and Guntanks are older models. Hell Guncannons (at least by Volume 3) can barely even hold their own against a single Zaku II when fighting solo.
Although it seems that the Zaku II and the GM both have anti-personal machine guns built into their arms.