Suh's monster contract ($114 million, with $60 million guaranteed) only works if Suh performs flawlessly over the next 6 years.
The problem with the Suh situation is that there is extra risk that the relationship blows up, because coach Philbin & Suh could easily clash. Philbin emphasizes high character guys, and regularly rails against personal fouls. Suh is known as NFL's dirtiest player, and at one point was the league leader in personal fouls.
With all the character issue blowups in Miami that resulted in dumping players (Martin/Incog, Odrick, Wallace), it's certainly possible that Miami could be caught in a bad situation if things don't work out, and then Miami's faced with a massive cap hit and $60 million guaranteed.
When someone gets that much guaranteed money, they no longer have to cooperate. You have to HOPE they cooperate. After all, firing them would just make them richer, as they can walk away with $60 million guaranteed for one year of work, and sign another big contract.