I don't work for neither Ryanair nor Norwegian. But from my point of view it doesn't make any sense to leave Southwest for those carriers. Even if you might have a chance at getting in as a DEC you would be looking at 110-120K € max before tax. I assume that you already make more than that and pay less taxes in the US. So if you can upgrade in Southwest in a year you would only have half your salary here in Europe. Is it worth it?
And from your Ryanair salary you have to pay your medical, uniform, parking at the airport, hotac for simulators and much more! Even the water on board!
And remember that getting an EASA license needs a lot of studies for the written test!
All the best!