The higher fill "power" (650-900 fill) IS warmer RELTATIVE TO FILL WEIGHT. So a 900 fill power is warmer than a 700 fill power with the same fill weight. So if they both have 5oz of down (weight), the 900 power will be warmer. But if a 700 fill power has 7.5oz, and another has 5.6oz weight of 800 fill, the first coat is likely a little warmer.
Example: Rab Neutrino and Positron both have 800 fill POWER.
Neutrino has 7.5 oz of 800 Fill
Positron has 10.6oz of 800 fill.
Thus the positron will be warmer, assuming both shells have similar wind blocking capacity. A puffer with a waterproof shell will be warmer vs. wind (Rab Valiance). So the four main issues are:
1. Shell wind blocking
2. Down fill power and anti-water treatment
3. Fill weight
4. Body coverage- hooded, is it long enough? good wrist seals, etc.
The reason this is confusing is that most manufacturers hide or do not even list the fill weight, since most people don't know it's a thing. I wish they all listed both values side by side.
I think you have already won. Both of those will be great jackets, so long as their packable size and weight doesn't annoy you.
However, in my opinion, little sucks during hunting like being freezing while glassing.