Johansen is not exactly a like-for-like replacement for Wellens or Narváez. Without the two of them there, only Vermeersch and to a lesser extent Morgado have the explosivity to do more than setting a consistent pace for a long duration of time, and a consistent pace is not enough to make the race hard early.
Or to put it another way: if you take the whole UAE squad and pick six riders to make Ronde as hard as possible, then when everyone is healthy, Wellens and Narváez are two of the three first riders you pick (together with Vermeersch). The seventh- and eighth-best options now replacing them just aren't going to be able to fill that hole, and therefore just like last year UAE will have to manage their resources a little bit when it comes to setting up Pogacar.