Could be a number of factors.
When looking at sensitivities of component sets you have to be VERY wary of how the sensitivity is measured.
First is, and I've seen this a lot is the manufacturer uses the most sensitive driver, the tweeter to measure the sensitivity of the set. So, you have a set that's rated 93db @ 1w/1m. Well, they're probably using the tweeter. Not at all accurate.
Another is, when you take two drivers of the same diameter, and same impedance, but one is 3 db more sensitive, it's a good bet that it will not have the low end thump of the driver that's 3 db less. Hoffman's Law VERY, VERY simply stated. Give me a break guys. Go to
partsexpress and take a look at the sensitivities of an 8", 8 ohm home audio driver, and an 8", 8 ohm pro audio driver. You'll notice the pro-audio driver is much more sensitive in most cases. That pro-audio driver will not have the same low end attack though.
There are a ton of other other variables as well. Unfortunately, we exist in a market where truth is subjective, and manufacturers can play with numbers.