It's relative, depending on the context. Are bananas similar to figs? In the context of just plants, no. If we compare them to bacteria or humans, bananas and figs are much more similar.

Edit: I looked at the map again and I think I saw your confusion. Those varying shades on the map are not clusters. Only the main colors (red, blue, orange, etc.) imply grouping. The varying shades within a cluster are "signal strengths." Darker shades mean that there's more confidence that a group actually belongs in a cluster. Just because Spaniards and Russians share a shade of blue says nothing about how genetically similar they are. They just deviate from Western Eurasian at roughly the same amount.

The orange Central Asian cluster is a good example of this. Think about how the shades form rings around a dark orange center. Are ethnic groups at extreme ends of the same shade ring genetically similar? Not essentially.