Why does the base phase appear so different between major coaches? Not necessarily the training for the base phase (they seem about the same) but its emphasis/importance.
Lydiard and Hadd: it's probably the most important phase, and the most emphasized in their publications.
Canova: base phase is just one of the four phases and should be done.
Daniels and Pfitzinger: "oh by the way, before training be sure to run at least X miles" (but it does not seem to matter how, as long as you do it).
Hansons: base phase is incorporated in the training plans.