Background: http://s19.photobucket.com/user/Pate5/media/rauniot4b.jpg.html
Gundam colored from one of my own submissions.
Bruticus colored/edited from an old sketch: http://d.facdn.net/art/megabeck1753/1459200045/1459200028.megabeck1753_g1_bruticus_sketch.jpg

I'd figured that out of all the combiners in G1, Bruticus seemed to be the most "Gundam-like" in aspect: The Combaticons are military-themed, just like Gundam. The individual robots(minus Swindle) have heads similar to the GM as well as other mobile suits of the Earth Federation. Brawl being a tank reminiscent of Guntank. Onslaught, the core leader bears a striking resemblance to the Guncannon. And finally, Bruticus himself for having a similarly-shaped faceplate chin and wields a beam rifle also similar to a Gundam's. So I thought "Sure, why not." by pitting the first real robot against a military-themed combiner.