This makes sense to me. Not all traders need precise rules BUT I think ALL traders need a process / checklist of what's essential for them to review as well as to get them in the right mindset for trading. For instance, I have 5 key macro indicators that I have to review each day (there are more that I look at but these 5 are essential). Then, I have to identify my key levels for each market. Lastly, I have to review each market in 3 key time frames. I also have some mental prep that I do around mindset.
Again, it's a process / checklist but not precise rules. This fits with a lot of the mindset training I do with young athletes, in particular baseball players. What I want them to do is go through their processes and routines which will allow their subconscious mind to give them the best chance for success.