I wouldn't say spreading the floor is impossible,it's just that players aren't built for it.
I'm pretty sure you could do that by making sure your players have have JR but low DR. That would mean that they would rely more on just straight Jump shooting rather than trying to create their own shot with a drive.
Also, add some passing on those guys with high JR and I'm pretty sure they will get a lot of assists from dishing to the big men.
Lots of people say JR doesn't effect the game engine other than just making shots and I dissagree. During my time having different players with a variety of JR I notice that those with higher JR tend to hand out more assists with less passing. Also, those with high passing but low JR tend to not have as many assists as one would think because they don't spread the floor well.
Just my thoughts about it.