Yeah, I think charms is a possible first tech if you start right next to a crystal with at least 4 materials and you're teching for early trained units...
Basically, if you would normally pick leatherworking but start next to crystals, charms might be an option.
I don't like the idea of the ToD requiring training. First off it doesn't really fit the flavor of the building, secondly it's a bit too harsh on undead, which already have a hard time at the start of the game.
And while Training might be rare as a first pick, I think it might be quite common as a second pick, to get drills third.
If anything where to be done to boost either, my suggestions would be that it's something that will only affect the very early game and soon becomes redundant.
Training: Training costs -5. Note that it says -5, not -5%. This will be useful if you want a bunch of troops early in the game, but late game won't make a dent in your production costs. Dropping your spearmen from 80 to 75 may mean you train them in two rounds instead of 3. Dropping your knights from 220 to 215 won't be noticable.
Charms: When finished with the research, you get 3 crystals. This would be enough to outfit a single squad with one type of magic gear. If starting next to a crystal cove, it means you can immediately train a squad with double magic gear.