This is my thinking. Murray or tank. The 2020 class should be significantly better, but I don't think any of the QB's will be notably better than Murray, and I'm very high on Tua. Murray was arguably the greatest HS QB of the last 20+ years. In 2018, he put up a season as good as there has been. He had elite throwing talent, is smart, instinctive, and has the quickest feet I've ever seen in a QB. He'll also likely run in the low 4.4's (projected to run as fast as 4.38), which is just icing on the cake, but given how great he is in the essential areas, it's fair to be impressed by that kind of speed. There's no question that his physical attributes on the whole are a significant advantage (will put a ton of pressure on opposing D's), rather than the detriment that many are claiming.
If you want to knock Murray, I'd say your best angle is pointing to his limited experience. I think that's a fair question to raise.