There's no need to comment on the eyes or brows right now, they're hardly even near done. I know they're terrible and lopsided at the moment, they're just quickly stuck on.
Now, I would like to know about muzzle shape again, and cheeks this time.
I've done a mock up cheek on the right side, as you can see here:
the cheek is just pinned on at the moment. There is also no lower jaw at all at the moment.
This is the left side, with no cheek at all added it's just a flat shape, just for basic shape comparison:
and here's a front shot:
Basically, any help or redlines that you can give on basic head shape, muzzle, and cheek would be awesome! They have such a strange head shape, I'm having a really hard time here D: