Mining with AMD Vega 56 with or without Nicehash

[ethereal1m]

Hello all,
I want to do profit comparison between mining using Nicehash or not using Vega56 GPU card. I use Whattomine profit calculator, and currently the best performance according to Whattomine, CryptoNight is having the best performance with daily profit around US$3.95 per GPU, whereas Nicehash Vega56 calculator yields US$2.22. Apparently Nicehash is mixing couple of algorithms like DaggerHashimoto, Equihash, and some small portion of CryptoNight, which ensues diluted profit.

Why Nicehash thinks that mixing those algorithm is the most profitable, whereas Whattomine says that pure CryptoNight will bring the most profit? Does this mean it is better off using the GPU without Nicehash?

regards