Dspringer, I will answer your questions one at a time as best I can.
Nothing in the book that I have seen says that Urial and Mother Winter are at the same level. What makes you believe they are equivalent?
Right, so
Uriel there actually have been multiple references both in-text and WOJ that say they are operating at the same level. I am not going to do all your homework here but there are several examples. Initially in the early books, in Summer Knight, Mab and Titania are considered to have power to rival the archangels and lesser gods (SK, Ch 23, p172). Harry then goes on to say that the Mothers are an order of magnitude above them. This is partially retconned as Mab and Titania in the later books no longer seem to be at the same level as Archangels, merely being at the level of the gods (not specified whether lesser or greater, or what the difference is between those categories, but very much explained that they outrank most gods). Jim also backs this up several times in interviews - he discusses that gods (or retired gods) like Erlking and Kringle, whilst being peers of Mab, are her equals. She is the boss of the worst of the worst for a reason. In their home turf they might be more dangerous to her, but that's the home field advantage. In Dead Beat when Cowl attempts to become a dark god using the Darkhallow (specified in the book as minor-league but this too may have been retconned in favour of him being greater), a question was put to Jim of who we had met thus far who could take Mab (assuming she was outside Faerie all alone, with no army or back up). Ferrovax, Titania (coin toss), the Mothers (who wouldn't), Drakul, all the White Council with her name, all the Reds, all the White Court, a union of the old Elders of the Black Court, and
Cowl if he had completed the Darkhallow. When questioned if Cowl would really be that strong from eating just a bunch of spirits, Jim replied that was how beings like the Erlking became so boss in the first place (which is why he is part of the spell), and that the power-sucking Stone Table isn't for nothing
Whilst Mab is powerful, there are WOJs describing fights between Angels as blowing up planets, which is why they don't generally get involved like that in the first place. Uriel doesn't even really do contested violence, as he just thinks about annihilating galaxies and it just happens. There are multiple WOJs on this. In text, Harry even says he
knew (like knowing with intellectus) that Uriel could take out all the planets everywhere just by thinking about them. There is even a really rare WOJ replying to a fan on FB in a private group where he said Uriel has ended universes. Mab and Titania are not in that league.
And finally in Cold Days, Harry even compares summoning Mother Winter just shy of calling up Lucifer himself. If that isn't a close enough comparison...
I would argue that "estimating how limited a godlike being is" would be the only way to measure the power of a godlike being. A more limited being is a more powerful being. Uriel is incredibly limited, while Mother Winter is so mysterious that it is hard to tell. Hades is very limited, although it is unclear how much of that is choice vs hard limits. Ambiguity on power level seems a feature of the dresden universe.
You could argue that Choice is what makes you truly powerful. But I am comparing Power (energy) and Will (the ability to direct that energy). In Summer Knight there is a good example of this. The Mothers ask Harry what happens when something is stolen (including power) and he guesses it can be hoarded (as Dragons do) and it can rendered valueless or sold (both of which are
change). When Lily is turned into a stone statue she is full of the power of the Summer Knight. She has a mantle. But as she is unable to express it, unable to use her will, the Power is rendered somewhat useless. Which is not to say that she has no power. She just can't use it at that point. But on the other hand, if you only have Will and no Power what can you do? Very little indeed. Which would seem a lot to something with little to no Will of its own, but to something with both Power and enough Will to use it - like another mortal for example - you are obviously at a massive disadvantage. It is all about the
balance, the ratio. It is clear as you get higher in one you get less in the other. But it doesn't change the fact you have it in the first place. So Mother Winter, Uriel, HWWBh all have strong limits. Yet in the right circumstances can change reality and affect everything on a incredible scale. So while it might be a little here or there in terms of their full bench press amount, it doesn't really matter. Power has purpose. So they can do what they need to do when it is the right circumstances for them to act.
Not sure this makes sense to me. There are thousands of gods, but there is only one Odin and only one Hades. So not really sure why your counts communicate anything about power.
Well actually we don't know that there is only the one Odin or the one Hades. That hasn't been established at all. But we do know that there is only the one Uriel, the one Lucifer etc. These guys are multiverse spanning beings - they operate at on a completely different scale. The fact that there is only a handful of these beings in all the multiverse, one of each individual in fact, shows that they are far more important to the overall cosmology than a Hades or Odin.
Also do not forget that there is a multiverse. There might be thousands of gods, but only a relative handful are active or engaged in any way with the Dresden world's universe. And it is not clear at all (until Mirror Mirror) whether Mab/Mother Winter exists in more than one multiverse. These other universes might have different guardians at the outer gates. It might even be possible that in some worlds the outer gates have fallen where in others they stand. So I can totally see thousands of gods of roughly equal power across the multiverse, with most of those simply not active or so limited in their access to the Dresden universe that they have effectively no power in that universe.
So pretty much answered this in my above point, but you basically make my point for me. We don't know that the gods are multiverse spanning individuals. Nothing in WOJ or in the books suggests this. We do know that Vadderung was theoretically aware of possible split universes, but wasn't 100% sure. He talks to Harry about this (specifically paradoxes) in Cold Days. And yes, while you may be correct that Mab may not exist across the multiverse, it would be strange if multiple Mother Winter's existed considering she is at the same level as other multiverse straddling beings. There indeed may be different guardians of the gates in different worlds. But they would all have a power source, who might wear a different mask in each universe. But underneath those masks is the same being. Mother Winter (or whatever is under that...)
It is not clear to me how you are determining Hades is at the same level as the mothers. The speculation that Hades is comparable to Hecate is based purely on mythology. But neither mythology or anything that occurred in the books would give any insight as to the relative power of Hades vs the Mothers. Can you please identify why you feel the two are equivalent?
I have never determined that Hades is at the same level as the Mothers. In fact I entirely disagree with that. Hades and Hecate were peers in mythology, but by no means was she the level of Hades. He had far more importance, and was considered so in ancient times. I was disagreeing with the comparison that Hecate is the being that makes up SIX Queens of Faeries, two of which are Archangel level. If Hecate makes up all six, and Hades is her peer or stronger, then he would have to be stronger than two Archangels plus extra and maybe a lot more so. Which would probably put him close to the Almighty. Jim's books give a lot of power to faith and belief, and Hades isn't very actively worshiped compared to the BILLIONS that worship the Almighty (in his various names - Jehovah, Yaweh, Allah etc). It just isn't rational. Now there may be no direct comparison in the books or in WOJ - probably because there really doesn't need to be. It is pretty straight forward with the pieces Jim has given to us.