Always a good subject that I am interested in too.
What I found with Massachusetts is though it is a bigger state with more water they actually stock less trout than Ct. Ct. choses to raise more fish up to two years old whereas Mass. raises less fish but far more at two years or older.
NY, being a much bigger state, raises more trout than we do but the streams I fish only get a minimal amount of brown trout averaging a little over 8" so their quality and quantity is poor for stocking but they rely more on holdover fish and natural reproduction plus a lot of money and effort goes into the Great Lakes.
When I fish Pa. and NJ their trout program is a lot like ours, raise as many trout as possible, stock medium sized fish in easily accessible spots for maximum return.
Hatchery resources is a problem in Ct. with Kensington hatchery dedicated to mostly atlantic salmon. If we did not have the salmon restoration program we could take Kensington and just raise browns and rainbows to 16" for quality stockings.
I like the Mass. program but it is expensive to raise a trout to 16 inches. But in general, I prefer to catch fewer trout but bigger trout.