I think he is more flexible and not stuck on in one formation at Ajax. Maybe higher expectations and pressure with United. It lead him to take lesser risk choice.
I saw him use DVB and Eriksen at the two nr.8 in a pre season match this summer. Like this:
Eriksen - Fred - DVB
But in all the league matches this season has been 4231 formation. Where Bruno is not a natural winger. Have to play RW/RM. Bruno hasn't pace to beat players at RW/RM
Here is a right foot natural right winger:
United legend Andrej Kanchelskis
Challenge for United current RW options. This the top level or RW/RM if you want to reach. Have a goal to reach and beat.
Watching Bruno and Sancho playing RM/RW make me miss United legend Andrej Kanchelskis . That man was really close to world class level as RW/RM player.
The point if. If you don't have a natural really good RW/RM player available. Drop a formation that demand a RW and go for 4312 with 2 really good CF upfront instead. And have another cm player for cover the midfield area.
That is why 433 and 451 and total football formation really really compact. In defensive the wingers track back to make a 5 man midfield. It make the midfield really compact.
4231 without natural really good wingers. It's not a good idea and decision from my point of view.
Imagine having Giggs and Kanchelskis as United wingers and wide players in this current team. It would be pure pleasure to watch. Wingers just keep it simple and beat players. Beside scoring goals.
In other words. I am not satisfying with United current level of wingers. Those legend are the standards and the top level of United and football. A challenge for them. To reach and become better players.
The basic = Right and best player for the specific job. Not a natural RM player Bruno as RM. Then you will limited your team max level. Bruno has and will never become a top or conistent really good RM. But as LM/LW maybe. But as RM. You need top speed to beat opponent defenders or at least world class crossers for Beckham. Top speed of Kanchelskis or top crosser and passer of Beckham. If not at and against top level opponents it will not work out.
When you have been spoiled of the top level of RM and wide players in Kanchelskis, Beckham and Giggs. Got served by the level of and qualities of United current wingers. Of course you get dissapointed.
It's all about effective football with end product. Keep it simple