It is interesting to see that McCarthy did steal from himself, he uses almost the exact same cue from "The Die is Cast" in the Generations soundtrack.
Other way around. Generations
I once saw a quote from McCarthy saying that he reused the Generations
cues to see if anyone was paying attention. Obviously a lot of us were. (Or maybe he meant he wanted to see if Berman was paying attention? Berman -- and Lauritson, I guess -- discouraged the composers from reusing themes and motifs, and maybe he was testing to see if they would even notice if he did. That's just speculation, though.)
I always found it amazing how Chattaway was able to work in a Leitmotif for Species 8472 and The Borg in Voy's Scorpion and the Dominion in "A Call To Arms" on Ds9 all within the same time period and get away with it.