Love to keep both and they may try to do that. IMO Littleton covers more need areas than Dante. If we don't keep Weddle Littleton has called the defense before and did pretty good. Dante offer sacks and pressure, pressure IMO are more important because they can cause miscues by a QB, INT's penalties (holding etc). Littleton however can play coverage, tackle decently in the field, intercepts balls, causes fumbles covers fumbles and also can be a force in ST with blocked kicks, and he also has blitzed with success at times as well.
Having AD on the field can assist a guy like Dante more so than what Littletons' areas of need. I see the true need for outside /edge rushing need and it is big, but overall for a good D you need a guy who can do more things overall.....IMO make Littleton primary to keep, try your best to keep Dante.