To solve this quest in Act 3, I have to put a lot more resources into recruiting than I actually need. And they will vanish afterwards anyway. What will I lose if I just decide to ignore this quest? Is there anything dependent on this quest (like the endgame quest or endings)? I already got the achievement in another playthrough.
About 90% certain it will affect the conclusion slides. Perhaps you can continue and update this to 100% certain?
It affects the later game in the following two ways:
Some council decisions you make in Act 3 is carries over in Act 5: buildings and units available are obviously the case; diplomacy also has two variations (Isger or Andoran).
If you miss some of the Act 3 rank-ups, in Act 5 there will be a crusade event basically says Galfrey did those while you’re away. I don’t know how exactly the game makes the choices for you; it’s probably random.
The game keeps a counter called CrusadeGlobalCounter. Every time you have a council meeting, this counter is increased by 1 (some choices also increase the counter). If you miss the meeting, you miss the point.
This counter will affect the crusade diplomacy part of the ending (one slide). The better slide requires the counter to be higher than 25. The total point you can get is around 28.
You also need the counter at 28 for one of the steam achievement.
Oh, so it’s ending-relevant. Thanks. Wouldn’t want to miss that.