When Rasmus Hojlund was signed last summer, a lot of people were of the opinion that he was going to play a very big role in Manchester United's proposed resurgence but unfortunately for Denmark international, he wasn't able to live up to expectations and that's why the club management are now trying to bring another world class striker that'll challenge Hojlund for the club's no.9 role cone next season.
Aston Villa striker Ollie Watkins have been incredible this season and is regarded as one of the best strikers in the English Premier League at the moment so I understand why the management Manchester United are trying as much as they can to lure him to Old Trafford this summer. I think it'll definitely not be an easy decision for Aston Villa to let go of their best player at the moment. There's still a possibility that Watkins might leave the club but for that to happen, Manchester United will pay a huge sum of money.
Manchester United seems to have failed to utilize all their big signing players like Sancho, Anthony and Hojlund. Seeing this pattern, signing another attacking players won't give a better impact on their offense line. I really don't think this problem comes from the ability of the players. The management and Ten Hag himself need to find the cause of the problem before they prepare the plan for next season.
With the way of how the team play, I don't think Watkins is a good option to revive the attacking line, or even Watkins shouldn't be an option at all. He doesn't suit transitional attacks with long through-ball passes. Moreover, Aston Villa won't let him go after achieving the top four finish that will guarantee them playing Champions League next season.