So:

Leinster 14
Ulster 7
Connacht 5
Munster 4

What is going wrong in Munster? The current batch of u-20s would've been 11 or 12 when they first won the Heineken Cup.

5 Connacht players included in the 6 nations squad, the only one to miss out was Pat O'Toole but I think he was injured before christmas

Ireland U-20 Squad, RBS 6 Nations 2015

Samuel Arnold (Ballynahinch/Ulster)
Harrison Brewer (Terenure/ Leinster)*
Ross Byrne (UCD RFC/ Leinster)*
Joey Carbery (UCD/ Leinster)
Fergal Cleary (Lansdowne / Leinster)
Jack Cullen (Shannon /Munster)*
Billy Dardis (UCD/Leinster) *
Lorcan Dow (Queens/Ulster)
Jack Dwan (Leinster)
Stephen Fitzgerald (Shannon/ Munster)
Ciaran Gaffney (Galwegians/Connacht) *
Oisin Heffernan (Terenure/Leinster)*
Michael Lagan (Ballymena/Ulster)
Jeremy Lougman (UCD/Leinster)
Zac McCall (Queens University/Ulster)
Nicolas McCarthy (UCD/Leinster)*
Sean McNulty (UCD/Munster)*
Stephen McVeigh (Buccaneers/Connacht)
Rory Moloney (Buccaneers/Connacht)*
Josh Murphy (UCD/Leinster) *
David O’Connor (St. Mary’s/Leinster)
Conan O’Donnell (Sligo/Connacht)
Conor Oliver (St. Mary’s/Leinster)
Greg O’Shea (Shannon/Munster)
Jack Owens (Queens University/Ulster)
Garry Ringrose (UCD/Leinster)*
Cian Romaine (Buccaneers/Connacht)
Jacob Stockdale (Queens University/Ulster)
Alexander Thompson (Queens University/Ulster)
Nick Timoney (St. Mary’s/Leinster)
*Denotes previously capped at this level