You need both. Iniesta had electric acceleration that enabled him to go past a player or two. Xavi was just about a walking statue, but he was like Scholes with arguably more finesse, so he didn't need physicality. They also had Dani Alves who was very quick, Alba in his prime, Messi, Eto'o, Villa etc who all had pace. As you said, it wasn't their trademark, but they were arguably the best technical team in football history and they still had runners - they weren't a great transitional team though.
You can build a great team from different perspectives and strengths. My concern with the current United crop is that we aren't particularly brilliant at anything. I don't think we are very poor in either category either, which makes us a fairly balanced team in that regard, which also makes us overall a fairly decent team.
However, most top tier teams have a clear strength - something that other teams have to worry about. We used to have a electric attack that were arguably the best in the world at counter attacking football and transitions. Mourinho used to have the most physical teams in the world. Arsene Wenger would go with technical. Where is our identity?
If you want to be the best in the world at transitions, as ETH stated, then we need seriously fast players, and we need brilliant passers from deep. Where are we in that process? Højlund looks properly fast, so he might transform our team. Rashford is fast, but he lacks a proper work rate. Antony has decent pace, but he's a train wreck in transitions. Garnacho is fairly fast. Martial can't run anymore. Bruno is fairly quick for a number ten, but nothing to write home about. Our fullbacks are quick, but not Evra quick.
We certainly don't have the Xavi, Scholes passers in the game - hell not even Carrick. So how exactly does ETH see us becoming the best transitional team in the world?