I think Martial plays the striker role well in his all round play but I think the consistency of goal scoring isn't quite where it needs to be, but in fairness this is only his second full season playing week in and week out as a striker.
If we did move full-time to a two striker system than Haaland definitely would make a better buy than Sancho, I mean a quartet of Mason/Haaland/Martial/Rashford would be the most diverse and high quality set of striking options we've had since the Cole/Yorke/Ole/Sheringham days.
And this is why I think Ole went for Haaland (and why we went for Ighalo and Cavani after that failed).
There is some fans that want to sell Martial when we get a more predatory striker but when you look at a team like Arsenal and how they use Lacazette centrally to try and get balls in to Aubameyang in from out wide - I think Martial is one of the best we could find to do exactly that as
one of our tactics. He can also cover LW. There is no reason to sell him because he gives us a versatility in how we play our forwards and formation.
Rashford looks like he is capable LW aswell as a CF that gets behind the defensive line (a bit like young Aubameyang).
Greenwood can play RW aswell as CF. I was also surprised at his ability to shoot from long distance and not just in the box all the time.
If we get a striker like Haaland then our 4 strikers are very flexible to adapt to our need of tactics. For example, Someone like Telles & an attacking RWB becomes more important to Haaland than the other strikers we may play. Likewise a defensive fullback on both sides with Shaw & Wan Bissaka may help us to play the ball more on the floor and more centrally to suit our current forwards as we saw last season when they were out scoring the rest of the PL.
I still believe that if Ole is manager when Haaland is available that we will have a very good chance of buying him as he rejected us only to develop in the Bundesliga.
Even if Ole's tactics might not be perfect all the time - I can see what he is planning to do with our squad. A fully capable and flexible group of 4 strikers that have different ways of playing. A flexible mix of 2 attacking and 2 defensive fullbacks. Have CAM, that are able to play as CM or even further forward. Have CM and CDM that are able to play at CB to create a flowing back 3 when needed (Mctomminay, Matic and getting linked to a player like Zakaria).
I really like the way he is building this squad.