The other factor about the Irish sides, and this is what really winds me up, because they are centrally contracted, they are paid for by the IRFU so it still gives them the ability to have one good local (as in Irish) and one good overseas player in each position without spending more. Thereby maintaining a good league position whilst resting the key players for Europe and Internationals.
Moan all we like (and we do!) about Saracens but at least Farrell, Itoje, Billy V etc play most of the club matches outside of International and European windows.
If we ring fence, it won't be long before we go Franchise and then European franchise etc