I believe the only way a 'Small Market Team' benefits from taking on a High Cap to help them get closer to the Cap Floor is if that High Cap player's Salary is low but his Cap Hit is High -- the Pronger example quoted above is a perfect example -- It makes no sense to me for such a Franchise to take on a High Cap Player that they don't feel is worth it... or they don't actually want... when they can actually spend the Cash Salary on a player they desire. They can even over pay if so inclined and be in a better situation than taking on a player's high Salary who is under performing or doesn't fit their needs/wants.
If they like MacD and feel he is worth the Cash outlay then by all means they should take him... but if they merely want to reach the Cap Floor, it would be foolish to take him, and would be better to spend or even over-spend the Cash on a targeted player... Or find a Front-Loaded Contract Player who has reached his bargain years and who is no longer wanted by a Large Market Team in Cap Hell.
If Hexy can sell Arizona on MacD's upside he may be able to trade him there... and while he's at it he may be able to throw in the Title to the Walt Whitman Bridge as a sweetener.