The fact that all the robots looked so different struck Lex as unusual, but he quickly noticed a pattern in their bodies despite the varying shapes. First, regardless of whether they were shaped like humanoids, tetrapods, floating orbs, small jets or whatever else, they all boasted a large torso, or central body.
It was not so evident when they were shaped like humans or animals, but the feature became more prominent when they took other shapes. Still, Lex would not have noticed this if it weren't for the fact that his soul sense could detect wisps of souls exactly in those spots. He did not know how significant this discovery was, but it could prove to be useful.
The second, more obvious thing that he noticed was that despite whatever form they took, they all seemed to be using laser weapons. Sure, the weapons had various forms, but all of them shot lasers - regardless of whether they were in the visible spectrum or not.