Good post, and an interesting take. I think a lot of the talk of Antho being a 9 in the traditional sense seems media driven, reports from the player himself wanting to be the main man not just a left winger. I would agree with the players we have the front 3 could be very fluid and move across the pitch freely, but that then questions the sense of signing a Haaland type as we would have to change our style of play once more.
AM can hold the ball well and link with runners centrally but has a tendency to drift left so he encroaches on the left players space, and leaves an empty box for the fullback to cross into and we lose possession this way a lot.
Absoloutely agree with your point about what he said he is trying to become. It's personal responsibility for Martial to admit he's a player who likes to be on the ball and abandon this Box 9 obsession. He has to make his own mind up to realise he ain't going to be succesful playing that way.
Rashford was faced with a similar decision few seasons back he was doing interviews saying he see's himself as a ST (this was when everyone was liking him to R9 early on and he was wearing the R9 boots). It became more apparent as he developed that the position weren't for him, he now gives a very different answer.
Our fanbase gets tricked by the media in my opinion the easiest. The media told them "Lukaku isn't good" they hated him. Now they want a player like Lukaku. The media now tells them "United need a Box 9" it's a now a new hole we need to address. "Pogba is rubbish", they now hate him, Pogba leaves "we need more creativity" (mark my words this will happen). But the players fall for it too and I believe Martial hinting through the media he wanted to be a more traditional was probably him trying to play to his fan service. Critical and independent thinking has left a lot of people - I think a lot of the fanbase is slow and quite gullible. (Personally I watch most games on mute)
Love Cavani would love to keep another season beyond this, but if I had to pick Cavani last season, or Martial when he was a fluid forward-player the season before. I pick the latter everytime that breakthrough season including Greenwood was some of the most scintillating forward play I've seen in a long time from the trio all our forwards scored goals then not just the one CF (front three alone ended the season with 60 odd in total) .
Personally I don't want a box striker we play so much better upfront when everyones moving. Only one I'd accept would be a Haaland but like you said we'd play so different if we got him, however, Haaland has a lot to his game would be interesting to see how that translates to the PL.
When Martial goes out left you're right he occupies space there but some of the one twos we have produced out there has engineered some fabolous goals and combinations. With Shaw Pogba Marcus all assisting or scoring. The space created in the middle by such movement ideally would be for Bruno or a Greenwood to attack. If you observed the Leeds game when Greenwood drifted and created space, Bruno looked like he was playing CF at times he timed his runs and attacked the space very well.
If Martial was to create space cause he drifted left while playing CF and was hanging there, the whole point of it being 'fluid' is for anybody else to exploit the central space in their own way.