No idea, seems that ETH wants to feel comfortable lining up players he knows and already worked with. It's kinda concerning though because nobody in his right mind would spend 100M on Antony so it's obviously a strong request from ETH.
United's plans don't make sense to me. You already have Sancho and Rashford on the wings, developping these players should be a priority. Then spend 70M on a striker, 30M on a good prospect on the wing and you're good to go. Who knows what will happen with Ronaldo but if he leaves, you end up with Rashford, Sancho and Antony competing for 2 spots and Martial (or occasionnally Rashford) as strikers, I don't understand what they're trying to achieve.