"the lines between the two are often blurry"
Aye, there's the rub. Here's the problem, a "crossover" is usually little more then an 'SUV' built on a uni-body platform instead of body-on-frame and usually FWD. Those have been around for many, many years, just no one called them 'crossovers'. Then came a few that had more car-like features, or more truck-like features, so some advertising someone somewhere coined the term 'crossover' to describe their company's vehicle in an attempt to set them apart from the pack. So now, we retrospectively apply the term 'crossover' to just about any vehicle the combines bits of two or more other vehicles into one.
You could have a valid argument that the Sport Trac is a crossover. It was the full cabin benefits of an SUV, but with an open cargo bed of a truck. As with all crossovers, there are sacrifices. You cannot sit more then 5 people in the ST, where is other SUVs of the same size can seat up to 7; the truck bed cannot hold as much, where other truck of similar size can hold much, much more. But no, no one calls the ST a crossover, instead, they call it an "SUT", Sport Utility Truck. A crossover name if there ever was one.
If you want to compare similar models, you must look at cars with similar prices, features, capabilities, and audience. Don't fuss over what the manufacturer wants to call the vehicle, as they'll call it anything in order to make it different.
