The roster spot is more valuable than the cap space. We have so much of latter, that we can't spend it, and certainly shouldn't. It'll be better to give a nice bonus to the players to reach the floor, than spend it.
While it will be good to get some picks at the cost of picking some bad contracts, no point taking on long term dead weight. Reduces flexibility later.
As of now, excluding Ben and Arron, we'll have 7 players. Adding 4 more brings us to 11. This gives us lot of flexibility in terms of buying picks, bringing back one or both of DC/Lawson, extending a qualifying offer to Ben, etc. Hope we can make it count.
Finally, I wouldn't have minded if LG had picked his option and stayed with the team. His contract was reasonably small, he's still young, and was not bad in limited minutes with us. We might have been able to get something for him at the trade deadline. No big deal though.