This is how I would handle those players. I would restructure both Smith/ Harper deals to make them trade friendly if the players agreed. A trade means you get something of value instead of just a dead money acceleration... if they do not agree then they will be cut.

Regardless of agreement, I would designate Greer and Harper as post June 1 casualties. What happens then is that the cap is effected as outlined below.

Smith Cap Figure $13.9m / Dead money incurred for 2014 2.3m Frees up 11.6m.

Harper Cap Figure $5.8m / Dead money incurred for 2014 $3.6m Frees up $2.2m

Greer Cap Figure $5.8m / Dead money incurred for 2014 2.6m frees $up 3.2m

Moore cap hit 5m / Dead money incurred 2.3m frees up 3.7m

Sproles is in the last year of his contract Cap Figure 4.3m dead 750k frees up 3.5m

Estimated Cap Relief with out exercising 2 June 1st players $24.2m

Estmated Cap Relief with Harper and Greer designated as June 1st Casualties. $27.6m

The June 1st designation forces the 2014 part of the prorated bonus to be counted against the team but the remaining years are moved to 2015's cap.

Colston for example.
With out the J1 designation
8.3m Cap Hit / 10.1m in dead money if cut - (-1.8m) cap loss
With the J1 designation
8.3m Cap Hit / 2014 - 4.5m In dead money , 2014 6.7m in dead money. A cap savings for 2014 of 3.8m