Re: Much cheaper.
Yes you can compare WFH here with WFH there.
Now, UK managers are already having a mind-struggle with UK based WFH workers that used to be office based, never mind Croatia based ones. And a legal payroll mechanism is needed for say, Croatia.
The real corporate dream is move whole departments including the 'prep monitor' to Eastern Europe or maybe even India at a fraction of the wage bill. In this case the manager himself may experience an existential crisis.
The WFH-only comparison works where there's a compelling use-case, i.e. employing experienced specialists with a massive track record. That's usually developers or consultants.
In your case it looks like you're exceptionally confident and nimble and have solved the payment/EU employment regs issues.