While characters with 46 experience, I've noticed that the character advancement tables encourage players to plan their characters' advancement paths rather than spending experience on the areas they find most entertaining. For example, a Kuni Purifier that wants to be good using melee or ranged weapons needs to raise those skills at Rank 1 or Rank 4 if he wants the experience to count toward advancing in rank. Furthermore, any Earth Invocations he gets past Rank 1 won't count toward advancement until Rank 4. This is true even if that invocation is Bind the Shadow, one I suspect almost all Kuni Purifiers would encourage their peers to learn,, or Courage of the Seven Thunders, a thematically appropriate invocation for a school that specializes in fighting creatures so horrible they're rarely discussed by other clans.
Although I'm only creating characters for fun, I find it frustrating that I need to constantly ask myself if I'm raising skills at the right time. As a player, I'm sure I would be even more frustrated realizing that my Rank 2 Kuni Purifier who has just spent an entire session studying people in court for signs of the Taint should wait until Rank 3 to raise Sentiment, because he wants to be good at Performance and Government, skills that won't count toward advancement again until Rank 5.
In addition to forcing character advancement to be out of sync with the story, the need to plan characters in advance makes experience itself less rewarding. With a more open advancement system, I would say to myself, "I want my Kuni Purifier to be great at dealing with Shadowlands creatures but still useful in other situations, so I'm going to raise my Earth and pick up Earth Becomes Sky." Instead, I'm finding myself thinking, "Wait. I can't raise my Earth yet because I want the the skills and techniques available at this rank to count toward advancement. I'll have to wait to be great at using Jade Strike, Armor of Earth, and Bind the Shadow, even though they're techniques that are central to my school's theme."
In some cases, I also find myself thinking, "I want to raise a skill from Rank 1 to Rank 2, but I only have 2 experience left to advance to the next rank, and that would cost 4. I'd better learn a new skill that still counts so none of my experience goes to waste."
The easiest way to eliminate the need to plan characters would be to allow any experience expenditure to count toward advancement. However, that would make the only distinction between schools their school techniques and which technique categories they have access to. I may not like the advancement table, but I'm glad they encourage the Kakita Duelist to master art as well as swordsmanship, the Shiba Guardian to explore the finer points of philosophy, and the Hida Defender to gain the nature skills necessary to survive in the Shadowlands. More school techniques would help schools stand out, but since that is the approach previous editions took, I'll assume it was discarded for a reason, such as keeping certain schools from pulling too far ahead of others.
We could get rid of advancement tables and assign each school a list of skills and techniques that count toward experience. For example, the Kakita Duelist might have all Martial Skills, Courtesy, Culture, Aesthetics, Design, Smithing and all Kata count toward advancement, as well as gaining access to Crescent Moon Style, All Arts are One, and A Samurai's Fate a rank early. This approach would allow schools to stand apart, but it would also make it harder to create characters who break from the norm, such as the Kakita Duelist who has mastered survival and theology while serving as a shugenja's bodyguard and champion.
With that in mind, I'd like to suggest a change to advancement tables: Let experience in any skill count toward character advancement as long as it appears in the current rank or a prior rank. Under this system, the first rank or two would represent the skills and techniques the school considers fundamental or has a knack for, with higher ranks allowing members to be recognized whether they become experts in those fundamentals or broaden their capabilities. For example, the Kuni Purifier table might look something like this:
QuoteRank 1
Earth Invocations
Fitness
Martial Arts [Melee]
Martial Arts [Unarmed]
Skullduggery
Survival
Theology
Bind the Shadows
Rings
Rank 2 (reached at 16 experience)
Water Invocations
Command
Performance
Sentiment
Essence of Jade
Rank 3 (reached at 36 experience)
Fire Invocations
Commerce
Labor
Medicine
Rise, Earth
Rank 4 (reached at 60 experience)
Air Invocations
Culture
Courtesy
Government
Rank 5 (reached at 92 experience)
Martial Arts [Ranged]
Tactics
Rank 6 (reached at 140 experience)
You gain Purge the Darkness. Once per game session, you may spend 1 Void point to wield an invocation against all the wicked in your sight. Instead of affecting its usual number of targets, the next invocation technique you perform targets each being in range that you know to possess the Shadowlands Taint disadvantage or Shadowlands Creature ability.
Note: If you spend experience on a skill or technique that would count toward advancement at a later rank, record the experience expenditure in the appropriate row. It will count toward advancement once you reach that rank.
Like the current advancement tables, the expanding table approach would keep the schools distinct while allowing players to create unusual characters by rewarding atypical experience expenditures at higher ranks. However, it would also eliminate the need for players to plan their characters in advance to ensure they are picking up skills and rings at the perfect time. In addition, it would allow fun and mechanically sound characters, such as a Kuni Purifier that focuses almost entirely on Earth Invocations rather than dabbling in Water and Fire because those are the only invocations that count at Ranks 2 and 3.
The expanding table approach has the potential to be less realistic than the current advancement tables. The example table would allow a Kuni Purifier to advance by becoming a master of the martial arts rather than communing with the kami. I doubt this will be a major concern. Most people who want to play a certain type of character will choose a school (and school technique) that is appropriate for that character. If they don't, they'll still have an incentive to diversify unless the campaign is laser-focused on one area, for the higher, more expensive skill ranks have a less significant impact on players' chance of success than their predecessors.
The expanding table approach also retains some of the disadvantages of the current system, such as forcing people who go against their school's stereotype to wait a long time before their experience expenditures count toward advancement. However, I suspect it will still be more enjoyable than the current system.