A like by like comparison would be what the 2019 Renault PU could do on the back of the back of a Redbull chassis. As far as i can see Mclaren or Renault factory team do not have a more aero efficient chassis than Redbull yet are almost always ahead. And we are talking of a sample size of 12 races of varying downforce requirements.
What i feel by looking at Mclaren’s performance on straights Renault PU has an edge on straights over Honda powered cars. I think Renault is ahead albeit slightly on power both in race and qualifying while Honda is a bit more reliable