Jonathan Tah? He is strongly linked with a move to Bayern Munich. He wants Bayern Munich and they want him as well, all Manchester United did was to inquire about the player, no further advances has been made for him. He was part of the players that helped Bayern Leverkusen win the Bundesliga League Competition last season. I haven't watched him closely so I cannot say what I don't know. I agree with you, Erik Ten Hag needs a strong base to thrive, it was key to success in his first season for the red devils ( Manchester United )
So, that is the problem for Man United because they have to compete with Bayern Munich to be able to recruit this player. Apart from that, Bayern Munich will not give up on making an offer to Leverkusen at a higher price, while Manchester United doesn't seem to be able to make a higher offer than Bayern Munich.
Until now there has been no decision regarding either of them, but I really hope that Man United can finally recruit these player considering that the club really needs a defender.