I doubt the scenario is ever quite as good as the first time; after that, you know most of the 'tricks'. The endgame is tough because you don't anticipate Drifa. If you got the stag, you probably don't need to worry, you can run past Drifa and sacrifice your existing units in distracting him. Clearly, in that case, the ability to move Kylorin 3 is worth more than the Golden Age. However, once you have played the scenario and know that Drifa is coming, it is totally different, and she isn't that hard to counter.
Best wishes,
Breunor