I’d keep 15 over The Siege. It has better character development for Din as he gives up wearing the helmet to save the child (which is huge for him). The Siege is pure filler, with only learning about the experiments… but we already knew about that from Season/Film 1.
There will certainly be a lot to think about think about after next weeks episode. The biggest problem with this season is the Razorcrest. It’s going to be a massive continuity bind.