Yes FRying - I agree with you! The point is that presented with a roster change for tomorrow - i.e. position to ORY to operate, a UK pilot has no option if he wants to keep paying his mortgage!
The collective action you describe would have to be collectively organised but that would be a separate issue. This current dispute in France is related to their (i.e. French contract) pay negotiations - which is, legally, "nothing" to do with us - note I said legally not morally/collective good/sympathetic etc
The law is very much on the side of the company. In France, not so much.