The warmasters must have had some stress taking in the opinion of the people or they were really smart about what was going to happen..
Smaller starting Vault and heavy reinforcements (right before UW shows up) were the plan from day one. This makes much more sense because more cards means better chance for losing teams to get back into the game. That 12 cards we used in previous War, was pretty useless.
Originally Reinforcements were 48 cards, but the plan was to increase/decrease that number if needed based on what the current Vault situation was. I decided to increase the number to 60, which is two full decks, a good elementsy number, and put UW almost right in the middle (and slightly below average when looking at the average Vault count).
This is not something you need to be "really smart" about, it's just simple math. The reason why we had so many "UW will auto-win!" posts, is that players didn't know about Scouting and Reinforcements, both of which made big changes to Vault numbers. I tried to tell them that they do not have all the facts.