Didn't CJ make something crazy like $34MM this year? That has to be front loaded money.
But most of that is signing bonus, which counts equally for each year of the contract. Without looking up his deal, I expect he is carrying a slightly lower salary the first couple of years of the deal to lessen the cap hit, so it is actually slightly back-loaded. DWill's deal was done the same way if I remember correctly.
Let's say CJ's bonus was $24 million (just pulling that number out of the air for comparison purposes). JR could have paid $10 million this year in bonus, another $10 million next year in guaranteed bonus, and the final $4 million in year 3, also guaranteed. From a cap standpoint, it is exactly the same as paying the $24 million all in year 1. JR just did it all at once either because CJ wanted it that way, or maybe for other business reasons, i.e. tax liability, expected capital outlays, etc.