Whilst I certainly wouldn't be against it as a Plan B, I don't think this is the way Farke wants to use his strikers. To wholly generalise, that big unit striker is important when you want a quick out-ball when under pressure, and obviously to get on the end of crosses. Farke wants his team to build from the back, with patient passing. The strikers movement to create opportunities to receive passes in dangerous areas is then more important than aerial ability. So Pukki might play as a lone striker, even if he doesn't have the traditional qualities.
If we want to go longer, Srbeny and Morris can do a job on their own. So I would think any other striker brought in would be competition for Pukki to play in Farke's Plan A.