This seems to be an amazingly meaningless image without a lot more context and explanation. I don't see why showing it beside other languages helps at all either.
Maybe we could theorise about what's easier for programmers to understand. I'd suggest in that case that the more hierarchical systems are the hardest as the brain has more difficulty remembering small numbers of connections than a larger contextual web. But that's just an idea I would have looking at the images, I expect anyone who understands these well enough to draw conclusions from them would already be quite familiar with them.
Maybe we could theorise about what's easier for programmers to understand. I'd suggest in that case that the more hierarchical systems are the hardest as the brain has more difficulty remembering small numbers of connections than a larger contextual web. But that's just an idea I would have looking at the images, I expect anyone who understands these well enough to draw conclusions from them would already be quite familiar with them.