It is possible in theory as you say but as of now I can't see Nxt getting close to where ETH is now. Maybe if Nxt demonstrates that it does some things better than Ethereum on a significant level.
We certainly look forward to NXT being better than Ethereum so it makes competition more interesting, ethereum has proven to be a successful coin and the main factor is because it is supported by many tokens, hopefully tokens that use the NXT platform continue to grow and become popular.
It hasn't really proven that it is a successful coin. It depends on how you look at things. Sure if someone invested at $10 and sold at $1000 that's a successful investment. But as a coin Ethereum has a lot of trouble.