Ryanair seem to have staked out SkyEurope's other base in Bratislava and I don't think Bratislava is big enough to act as a base for 2 LCCs
Ryanair and Wizz have a habit of avoiding each other too...
Wizz recently moved all routes from Girona to Barcelona El Prat.
And most flights from Rome Ciampino to Rome Fuimicino, so the precedence is there for Wizz to comfortably operate out of a
"high cost" airport.