I do think Bruno is quality not just based on system and he also has very good character as footballer which he comes to United to win. Contrast to Sanchez when he came here.
But I do think he will be slightly less effective if he plays in system that can expose his weakness. You also wonder how he doesn’t make lot of assists in Portugal national team like how he did with Sporting and United.
Either way, we could make the same case that Pep needs KDB, we need Bruno and Klopp needs their full backs and VVD.
Sanchez shone at Arsenal be cause he had Özil behind him providing. Özil could find him with a ball where ever he went. However, Sanchez as a player costs you if you don't have a playmaker who can facilitate for him. He's sloppy with the ball, and chaotic in his movement around the pitch. He didn't fit at United, and could never fit under Mourinho who demanded his players defend and not lose the ball.
Bruno is the opposite. He's meticulous, and thoughtful. He fits. He doesn't provide assists in the Portugal national team because everything has to go through Ronaldo, and therefor most of the time the balls come to him from the wing, if I'm recalling correctly.