Trying to choose a suitable global eurail pass

Hi, some friends and I are going to be travelling around western europe for about 3 months (april-june) and we're trying to figure out what our best option for transportation would be.

We dont have a set itinerary but the countries we plan to visit and travel between include:

- ireland

- netherlands

- france

- spain

- italy

- greece

- austria

- czechia

- and germany

We want to have enough flexibility to be able to do day trips and slowly make our way from country to country, stopping at towns and cities along the way. l've seen that busses can be much cheaper than trains but would that be true in our case for the amount of flexibility and stops we may make?

We have been leaning towards getting the 3 month continuous pass but it is $1200. When I used the rail planner app it recommended we get a 15 day within 2 months flexi pass, would this actually be suitable for our plans?

I'd love to get opinions from people who are experienced with eurail and travel within the shengen area in general. Any help and tips are appreciated!!