As I already stated in the title, it feels like the show hast decreased a lot in quality in season 4 and this episode was a lowpoint so far.
It feels like they changed the writers or the head producers.
I loved the first 3 seasons. And this season is just significantly worse than the others - so far until episode 6 at least.
The whole season is like this episode : the plot is all over the place, stupid stuff happens all the time, cliche after cliche, trying to be a discount "Game of Thrones" (minus the big plot thread that keeps GoT together) - and so on.
And the loss of King Alfred in season 3 (though it is surely justified historywise) seems to be almost just as bad for "The Last Kindom" as the loss of Ragnar Lodbrok was for the rival TV show "Vikings".
Sorry for this rant and I don't want to write spoilers. I think the reason overall is that the writing got worse. Maybe the source material book on which it is based upon is just an exaple of the "weak one" in the series. I am just just disappointed to see this great TV show to decrease in quality so much. I hope it gets better again.
EDIT: After some research I found out that my feeling was right - the showrunner of seasons 1-3 stopped writing this show after season 3. So they really changed the writers. That explains a lot.