European Union Bill

Having lived in the United States, I absolutely share my hon. Friend's concern about judges' encroachment on parliamentary sovereignty. However, in the context of the Bill, is not he in danger of making the perfect the enemy of the good? Is not clause 18 a great first step towards limiting the abrogation of the sovereignty of this Parliament by the EU? By outlining a perfect situation, is not my hon. Friend in danger of making the enemy clause 18, which is surely a step in the right direction?