Top end D3 significantly may be better fit than D2 and bottom half D1 depending on the player.
Completely disagree. Unless your son is going to a NESCAC. And yes, low D1 can be tough, but high D2 is serious lacrosse. Go watch the Adelphi v Bentley game today.
Academics are average to below average at most D-2 schools
Agreed. And there are a ton of great academic D3's in addition to the NESCAC schools - Swarthmore, Babson, MIT, Washington & Lee, etc.