Just curious, but who are the "local knowledgable coaches?" Local HS coaches or LL/Pony coaches?
The SCVAL is broken up into 2 divisions...De Anza and El Camino in all sports. Schools can be in either in any sport. Generally, the stronger teams are in De Anza. How is that determined? Well, each year, the last place team in De Anza moves down and the 1st place team in El Camino moves up for the following year. This mechanism works generally well, but there are obviously no absolutes. One of the very best D2 teams in CCS last year was in the El Camino (Los Altos). LG is in De Anza, Saratoga in El Camino in baseball. Saratoga was forced down about 4 years ago after finishing last in De Anza.
Division 1/2/3 is based on school population...both LG and Saratoga are D2. Most WCAL schools are D1 because they petition "up" at the beginning of the year.
LG historically does have a much stronger baseball program (football too). I don't know about "anyone" making the Saratoga team, but the competition for playing time is not as much.
There are advantages to that, however. For example, a kid can make varsity sooner at a weaker school.
IMO, you should base your decision on where your son fits best overall...not just in baseball. Where are his friends going? Which school has the strongest academic program where your son's interests are (e.g. math/science, etc...)? Which fits your values (e.g. are you Catholic? do you value a Catholic education?)? Which fits your budget?
Some awfully good ballplayers have come out of "weak" programs in our area recently...some made their programs strong by their presence. As an example, our son's school (Mountain View) was something like 5-20 when he entered and something like 20-5 and league champs when he was a senior. Two kids from his team are now playing in the Pac-10. Several more at JCs and other smaller colleges...playing ball. Many of the comments when he entered MVHS were the same you're hearing about Saratoga now.
Find the overall school that is best for your son and your family and let the rest take care of itself. As I said, all 3 schools you are considering are great choices. Thats why housing prices are so very high in your area...its the schools!