I assume you mean RX 5700 XT and RTX 2060 Super, because those are closer to 400 dollars.
The 5700XT is much better price to performance, as it is as fast as an RTX 2070 super for significantly lower price.
With the 5700XT, you may get cooling issues with the blower fan, so you can spend a little more to get custom AIB cards, if you are willing to go a few dollars over budget.