Well, my statement was more looking towards next year, but I think you are being very optimistic in this statement.
We have 6 pitchers that would be top 4 for teams... Nola, Wheeler. Arrieta, yes, so far this season, last two years, no way. He wasnt horrible in 2018, but he was in 2019. Eflin, well, he is still fairly young and he has been a little below average in general, but at times better. You say we have 6... Pivetta and VV? Who are your other two.
Howard is still too early, but maybe if you are counting him. I dont think he has a grade yet, but he has been successful in the minors.
Not sure who you are referring to as these 6 pitchers. Maybe you were also including the bullpen, in which case I can see Neris in the list and maybe Morgan (although Morgan is probably not in a good teams top 6 pitchers, but maybe).
But like I said, my statement was more looking at next year, where we start with 2 starters. Eflin may be another. Howard may be another. That is at least the start to a starting staff, but I wouldnt exactly say it is a particularly strong staff unless that 5th starter is actually a #1 or #2.