It seems that there are 3 basic positions on what kind of "zeal" Paul refers to in Rom 10, Gal 1, and Phil 3.
(1) Trans-national Zeal - zeal for general obedience with an eye toward God (Rom 10:2)
(2) Inter-national Zeal - zeal for the Jewish nation and culture with an eye toward other nations (Phil 3:6)
(3) Intra-national Zeal - zeal for the Jewish nation and culture with an eye toward fellow (less zealous) Jews (Gal 1:14)
The NPP seems to see (1) as a subsidiary consequence of, and therefore subsumed within, (2) and (3); I am increasingly convinced this is exactly wrong: Jewish zeal for the nation is subsumed within moral zeal. Just about every time I read a contemporary book on Paul I find myself thinking that not enough attention is being given to anthropology (human capacity). Sanders and Dunn are overly optimistic on this point, and it sets off their whole thinking (due to a foundation that is a bit off). Specifically, we are wired to be naturally zealous about our own moral achievement. One ramification or illustration of this (deeper) zeal would be a nationalistic zeal. The vertical fuels the horizontal, not the other way round.