Objectively, taking off my Liverpool must be relegated at all costs hat, which I wear religiously...
If they were United players, you'd want both of them starting. Gapko is hot and cold but against us I thought he showed enough to demonstrate that he can be top class (may take years). The other, Ekitike, is actually top class (fan of his for years).
Isak is also top class (maybe not Halland, but a proven goalscorer).
So what do you do?
I'd play the three of them. And then three in midfield, two holders and a runner. Isak would have to be 9, whereas Ekitike can be 11 and Gapko/Whomever (Assume Wirtz and him are natural competitors) battle for the third spot.
They have, realistically, to do that or else get rid of one of Isak or Ekitike -- it makes no sense to keep both if you cannot play them in the same formation and the only way I see that working with the way they play is a 433 of some variety. 352 either, but as bad as we can be with something like a 352, we only have one relatively immobile striker (Sesko or Zirkzee) whereas they'd have two. It's not that neither can run, but you aren't going to get anything much in the way of hold up play and tracking back from two played as a two. So you move one wide as per Rooney-Ronaldo-Tevez (we had two wide, and each of the two, it has to be said, was lightyears better than any of their players even as a 9, in their primes -- now, they are nowhere near that flexible, in terms of the job that Rooney and Tevez [even Ronaldo at times] could do out wide).
They created the problem themselves and have no idea how to play with it. It's their own error. It's their midfield and defense which whatever about last season that I think is wank.