The hits from the tethys are double damage hits, thus the 10/5 shield absorbs 5 of them (x2 weapons take two shield boxes per hit).
The FAP FAQ should likely be called errata at this point given the misprinted books out there. (Not sure it was misprint myself, feels more like they changed there minds after the first run... but irrelevant.) And there is a formula that creates the breakdowns they list, make your initial breakdown, after that one subsequent point my be broken down one level, of the resulting points one may be broken down another level, repeat til patrol if desired.
ripple