L5R is not a video game. In my opinion, talent trees have no place there.
I can totally understand abilities with prerequisites (before taking this kata, you need this other kata, etc.), but taking SW has an example, you have abilities that are thematically related to another, but it doesn't make sense you have to choose them in a specific order.
''Why can't I choose this cool ability before having to increase my wounds, get another ability I do not want who have absolutly no relation to the first one and increase my proficiency with blasters?''
If the answer is balance, there are many ways to balance things and forcing players to get abilities they do not want is bad design.
Technically you have had that in every L5R edition previously. You just maybe didn't notice it because you were stuck on a single linear tree progression instead of a branching one. Probably every bushi or courtier or ninja school had techniques that you wouldn't want that didn't want at lower levels that didn't always directly impact the ones you wanted at higher levels.
Really, though, the progression of your techniques is going to be "video game like" regardless because all video game progressions are just table top progressions done smoothly and with more freedom to innovate and experiment than table top games get to. Dismissing talent trees because you first encountered them in video games? You might as well say "you want to put a table of contents in the book?! that's a terrible idea! Books aren't webpages!!" The only thing I can think of that would be really too 'video game' like would be if your skill progression was based on how many times you used the skill. That is the only system that would not work out as well or better in table top than in electronic games. After all, it is all good to say that you feel it is natural that people get better at a skill by practicing the skill as opposed to utilizing other unrelated skills, but how much of your game time do you really want to see players having their characters practice their skills to hone them rather than using them as needed?
That being said-- naturally talent tree branches with prerequisites should by all means have prerequisites be related to the later skills. If you want to learn how to fire two arrows a turn, you first need to learn how to draw your arrows quickly. If you want the technique to brace your spear against a horse, you need to learn the spear formation ability first.
Basically prerequisite techniques should be used only when higher level techniques are both better versions of lower level techniques and a bit strong for their "tier".
Although, generally, looking at the Star Wars RPG books, I see a lot here that could be adapted for L5R without too much extra work. There are some fundamental problems with the L5R mechanical system that would be fixed by moving over to a different mechanical system (i.e. the god stat problem, the useless skills that cost the same as critical ones, the fact that skills were functionally useless for their cost compared to attributes, the fact that some schools were far too powerful while others offered nothing of value, etc.)
Too many of the mechanics in 4E feel like they were put there because they seemed "interesting" and "unique" without ever really bothering to question as to whether they were properly modeling the world they were supposedly crafted to model. The way the attributes were set up for instance really shut out a lot of character concepts without much good reason behind it. When it is absolutely essential for your sickly healing shugenja needs to buy up her strength score in order to enhance her spell levels... you can be sure the cart was put before the horse when it came to designing the game mechanics.