By my interpretation such a reading would be a bit unnecessarily… ‘strict’ and might miss the chart’s much more general purpose. I understand it to be a tool for developing a loose overview of the key components that feature in descriptions of the gradual training across the canon (a more in depth engagement with the various aspects and their subtitles is naturally required for proper understanding).
At the same time, I think keeping in mind the dangers of getting locked into an excessively linear view is very important. I likewise think that it is definitely possible to read the chart as suggesting a fixed linear path, but to me that’s more a matter of mode of interpretation.