Let's get this in perspective. Ireland is a country of around 3 to 4 million people most of whom will have been baptised and educated as Catholics. In proportion to Catholics worldwide this is insignificant. The proportion who fulfil their duty of hearing Mass on Sundays and making their Easter Duty is more insignificant.
The referendum on same-sex marriage proved beyond doubt that Irish Catholics like most of their co-religionists in the West are pretty clueless concerning the teaching of the Catholic Church.
The ACP is a dissident group of priests who in times gone by would have been summarily defrocked. The largely anti-Catholic media in Ireland, however, give airtime to the ACP making them out to have some clout in ecclesiastical affairs.