Enough market size for both to excel. I would however, choose to focus on Nio. But that is because i want to diversify more into other sectors and dont want to split my ev exposure into 2.

There's no guarantee, but the likely higher intrinsic value betis Nio over Xpeng.  

Keep investing. NIO will be a market leader for luxury ev in China. They took the better portion of the pie in the worlds largest ev market.