If you want to bring the draw two argument you can. But you also have to realize it won't be a problem very often. It will with bad timing like drawing the second in the next 2-3 draws after using the first, in a non-combo match-up, with nothing valuable to do with it. The rest of the time you can just pitch one fow to the other.
In my list fow is also more often good at protecting the increased number of planeswalkers.

I don't think it's throwing away card advantage. Like I said the build with 4 wastelands+drs can out tempo quite often the opponent and the 4 fows are a good tool for that too. By running 0 discard main deck this version uses very well the fact that cascade isn't just card advantage, but can also sometimes add tempo value.