Currently most classes have six possible crowning gifts, but some of them have less than six. Barbarians have four and Beastfighters, Mindcrafters, Paladins, Thieves and Wizards have five. Priests might also need to be added to the list of classes with five possible crowning gifts depending on the exact implementation of this fix.
My suggestion is to simply add two more possible gifts to the pool for Barbarians and one for each of the other classes. This increases randomness and chance and decreases predictability by making it so that every single class in the game has a 1 in 6 chance of receiving a specific artifact as a crowning gift (or a 1 in 7 chance for races with possible special racial gifts). A little variety and unpredictability is in my opinion a very important spice in Ancardian life.
The new possible artifacts could be taken from the already existing artifact pool (good) or created anew as some of the new artifacts promised for the resurrection (great!).
I actually like it that there are a few crowning gifts with a double chance. There are only a few of those and I believe this actually means more variation overall.
I also like the double chances of some artifact gifts: it gives you something to look forward to. I guess one could instead introduce a non-equal weighting and provide 6 gifts, but it's kind of less fun.