Quite clearly, his heart just wasn't in it. "Galvatron riding Magnus... got it. Ho hum." It's kind of sad that someone who clearly KNOWS how to draw, would show such an utter indifference to composition and energy in the work.  

zmog

 

That's a point; maybe he didn't even know about or have reference to the original, and just drew it based on a note like "Galvatron atop UM's truck cab". Guess we fans take the iconic original for granted (particularly in the UK).

Still, that shouldn't be an excuse, since Senior probably worked from much the same note back in the day!