In impossible mode from the too numerous game scouting I tried:
Sacrifice:
- The 2 swamp Witch shops are the more frequent I noticed.
- Scroll on ground not far to young witch.
- Swamp Temple.
- In Cursed Child Castle, seen here once.
- An Hidden chest there is very often in Crypt with lost city book.
Gift:
- The 2 swamp Witch shops and Swamp Temple are the more frequent I noticed.
- Scroll on ground not far from Swamp Temple.
- Scroll on ground not far from Cursed Child Castle entrance.
- Third scroll of Mage Academy shop.
With Paladin I don't see why starting with Gift. Just select a game with Sacrifice should not be too long but with Royal Thorns + Tournament Helmet + True Faith Banner would be harder. And with the treatise this would require luck or many attempts.
Yes the Treatise can appear in Darion. I think the Tournament Helmet and True Faith Banner appear more often.
I could be wrong but I got the feeling that items and troops generated in Darion castles and shops has strong links with the hour in day you start the new game. I'm certainly wrong. Here for example a sample feeling I got: At 19H - 20H almost no chance to get knights in knight tent. At 6 AM - 7AM a high chance to get knights in knight tent.