Countries typically do not directly elect their chief executive by a simple plurality vote. There is usually some mechanism to force an outright majority. In parliamentary systems this is done by a majority of members, sometimes requiring a coalition of parties in parliament. In other countries like France the president requires a runoff vote so that a true majority of the vote is needed. Even in the US there are cities like Chicago and states like CA that have two rounds of voting to insure a majority is reached.
The US Constitution left it to the EC to create a majority, and if they couldn't come to a majority the selection would go to the House and they would need a majority of the states - a blending of popular vote and state vote. But in both rounds an outright majority is required. The defect of the NPVIC is that it permits the election of the national executive with a simple plurality of the vote. If the process included a provision whereby another round of voting would be required if no candidate for president got 50% of the vote it would be more consistent in terms of electing our chief executive.
I believe the states are supposed to have completed the process to choose their electors by election day. Note that this isn't the deadline to finish counting the votes. Anyways, they'd either have to have an earlier 1st round or something like IRV or condorcet.
