Tobacco is pressed first and foremost to more quickly mesh the juices of the different leaf to marry the flavors more. And, to me the whole leaf flake and plugs stick together better and make a more dense burning material to slow down the burn. But, cakes tend to fall apart, losing that slower burn, IMO.
I wonder sometimes whether the companies that make these either have to rely on another company to process one of the ingredient leafs for them, so they get the leaf already shredded, or if they intentionally do this in house because there are so many different ingredient varieties, with various degrees of percentages that shredding before pressing just makes the blend taste better. You know, like the recipes calls for 2% of a leaf, which might only be a partial leaf in a whole leaf plug, so most of the flakes wouldn't include that leaf making the flakes all taste different; whereas adding a pinch of shredded leaf may give you more consistency throughout the cake.
Either way, there are some cakes that I like, but I am never excited to see a cake when I first open a tin. I always just go ahead and break up cakes with my fingers and smoke them more like a ribbon. Otherwise I always end up with just a couple of smoldering chunks in the bowl at about halfway through the smoke.