As for doubting my launcher size comment, I did some calculations, and got the following:
Aft Launcher: 43.7 Meters
All Launchers: 16.2 Meters, and this is a generous estimate, you could argue that they are even smaller. The ones that are glued on are not on msd, but I'd say probably like 5 meters.
They are clearly not the same class.
I'm going to assume that you used the MSD's of both ships and made each one to the same scale (example 1CM = 1M) for both. Otherwise your calculations would be off.
We're using the same scale to determine launcher length; could there be even the slightest, most minuscule chance that the launchers on the 1701E are smaller because the launchers are more advanced, and therefore equal to, or maybe better than, the ones used on a Galaxy class?
And as been stated in dialogue that the Defiant carriers a big punch in a small body. Proving that bigger is not better. The desktop computer I'm using right now is much smaller than the ENIAC, and it has much more processing power than it's Great Great Grandfather (Not sure how many generations of computer there were between then and now but that should be sufficient.); hell I even think I read that my desk top has more computing power than the ones on the Apollo space crafts.