I have to agree with most of what you have said. Even if the Pezullos happen to buy another or new home in the Saratoga school district it will be really hard to not see this as an athletically motivated transfer. (Although perhaps no more than Murdock going from Toga to Shen in 2006 or Roxanne Henningson going from Stillwater to Greenwich in 2007.)
Pezzulo did run around 10:05 for 3K this winter and I believe has a slightly faster PR so if healthy (and given her career to date this may be a big if) I could see her contributing to Saratoga's top 3. But I still agree that their overall team caliber will probably be more defined by:
-how Keelin Hollowood continues to progress will she be able to mix it up at all with FM's top 3?
-how much improvement they get from their current group Borroughs, Hungerford, Freestone, and Treichel are all having good indoor seasons.
-Driscoll, and Morin both took about 90 seconds of their 3K times from last year (to get down to 11:05 range). They also have a 7th grader who went sub 11 any of these three girls could continue to improve and be a major factor in the fall
than the presence or absence of Pezzulo on the team.
FM has a solid 3 in Chapman, Fanning and Sischo in some order and barring catastrophes Martin and Malone should be enough for them at 4-5. I think Saratoga's chance against FM is to have a big advantage at 4-5 (and I'm not sure Saratoga really will have that). Saugus should also have a solid top 3 since I believe they return their top 3 and more Saratoga might have the advantage at the 4-5 spots against them depending on how both teams run on the day.