Maybe this is related to their thinking of selling Rashford? However he is playing as LW the most this season. Therefore I don't know why they plan to sign a 3rd striker for the team.
If they are thinking of parting ways with Zirkzee or Hojlund then I would understand. But I didn't see any rumour about these players to leave either.
I believe Vlahovic is more talented than both of those two though.
But if I were in their shoes, I would sign a LW instead of parting ways with Rashford. A really reliable one I mean.
I think it would be better for Man United to determine one of them but if I were myself I would prefer Victor Oshimen because this player seems to have a stronger mentality previously he was at Napoli and won the Scudetto and now at Galatasaray he also creates many goal opportunities, Man United is a big club they need players who have a strong mentality.