Depends. Martial compliments them a lot better but not sure he can be relied upon for a season.
In an ideal world, they would score more with Martial but it’s not as black and white as that in reality.
Regardless, they could have and should have definitely done better than they did last year irrespective of who they were playing with.
You last sentence makes no sense.
Should Ronaldo have been scoring 20 a season when the entire team was set up for Ruud to score?
Ruud did score, an awful lot. Weirdly when he left Ronaldo scored over 20 and hasn't scored less than that in a season since. Football is a team game, stick Bramble in a defence with Maldini, Nesta and Cafu and those 3 world class defenders will look lower than their level because a vital part of their unit isn't contributing what is needed.
If Ronaldo's job is purely to get goals then he absolutely did his job to a degree (Bruno scored more when he was our talisman). It is no real insult to him to say we are a better team without him though, not when he is 37 years old.
Rooney's best ever season - Year Ronaldo left
Benzema's best run of his career - When Ronaldo left
Rashford's worst scoring season since he came through - When Ronaldo arrived
Bruno's worst season in 5 - 6 years - When Ronaldo arrived
Sancho's worst season of his career - When Ronaldo arrived
Dybala goes from 26 goals to 10 goals - When Ronaldo arrived
Do you honestly not see any trend?
He needs to be the talisman and everything needs to be about him. This was absolutely fine when he was scoring 50 goals a season. He no longer has that in him no insult, he is approaching 40, the fact he can even contribute at this level is brilliant. He is just no longer worth it.