Not a dumb question at all, and I’ll speak mostly from past experience here.
Your average deer hunting boot advertised with x00 grams of thinsulate is simply not an ice fishing boot for a number of reasons. I own some of these too, but the first thing you’ll notice about these is the different construction altogether. On most of these types of boots, there’s a sole, stitched to leather uppers which have quilted insulation inside.
Pac boots are a different beast. Typically larger in the toe with more insulation (and air-space), these boots are designed for keeping you warmer in stationary positions, rather than being a hiking boot with warmth engineered as an after-thought. I’ve tried the Hiking/Pac Boot hybrids, and have never been satisfied with warmth or waterproofing.
I just picked up a pair of the alpha ice-kings this year through WorkbootHaven, so I can’t speak to their performance. That said, I’ve owned the same pair of Ice Kings (their predecessor) since I was a teenager, and they’re still the warmest boot I’ve ever owned. The Alpha Ice King is lighter, and appears to be more sleek and mobile than the older Ice King, which is something I’m excited about trying. Cold feet is no fun, and I’m confident that the Alpha’s won’t sell me short in that category.
Joel