First of many ?s....Heptarchal vs the Watchtowers?

[lpman59]

ok guys, here is the first of what will probably be many noob questions, so please take it easy on me.

so i have finished Tyson's "Enochian Magic for Beginners" and I feel like I have a fairly decent understanding of the material, at least for someone who has no previous experience with Dee's work. The Watchtowers break down the hierarchy and uses of the angels (ie Medicine, etc), but I do not understand the use(s) of the Heptarchal Kings, Princes, etc. Are they tied to the The Great Table the way the Airs are?

Thanks in advance for your help and guidance.

Edit: I reread the section on the Hept. angels and Tyson does indicate their uses (in a general way) and evocations.