I just got out my clippers and snipped under the armpit and behind some back scales. When it was removed I could tilt and rotate it down with the same scales somehow managing to form a pivot point and still stay mainly attached at the top of the shoulder. The gap in the armpit I filled out with bits of sprue - support which would be covered up with greenstuff.
I was so much happier at this point. You can see the Trolls face, which is amazing but also means I have to do a decent job on it! Having smoothed the armpit most of that will be in shadow anyway so it didn't have to be anatomically correct Some veins on the belly too.
I added a few scales onto the shoulder to help blend it in with the rest of the scales. The armpit is slightly more sculpted on the back, it looks something like skin and muscle stretching but it doesn't need to be perfect, luckily. You should also have noticed I've used a heavy red wash inbetween all the scales to make them look angry. I was using my turquoise Genestealer Aberrants for inspiration here.
Now that that unforeseen diversion has turned out for the best, it's back to painting this monster.