in a sense, that is the same general idea, just like how gentleman cho'gath, archduke Nasus, and the Debonair line are all the same general theme, just different facets of said theme. The same can be said of the heart seeker line and sweetheart Annie. They are obviously the same theme, just different (age appropriate) versions. It also applies to the arcade skin line, with Hecarim, Sona, and MF being part of the main line, with Final Boss Veigar obviously being in the same theme, but a different perspective on that concept.
Justicar skins being the hero they could have been is just about the same as Varus being the archer who wasn't corrupted. Vayne and Vel'koz actually don't fit into the arclight lineup, and it would have been better to leave Vel's skin as Arbiter Vel'koz (because it isn't showing a "good" version of him, but rather an otherworldly being judging the puny mortals of runeterra, i.e. and Arbiter). Vayne doesn't fit into that mould either, since she is always a "good guy".