Minor spoilers i suppose, please read at your own discretion
What would you rank the strength of each civilization between Ta Lo, Wakanda, and Talokan? Who do you think would win in an all-out war? Assume the place of battle is in Ta Lo, its hidden entrance, or a seaside/riverside location near said entrance but specify which. Additionally Namor is present alongside either Wenwu/Shang Chi for Ta Lo and any one of your chosen Black Panthers. The Great Protector is a factor ONLY if you assume the general populous of Ta Lo cannot handle it themselves.
I personally think Ta Lo far outranks both the others due to it being the literal home of the gods for Chinese deities. Think of it as being the equivalent of Chinese Asgard. And remember that what is seen in Shang Chi is literally just a single village of people dedicated to protecting the entrance to the realm and are not a complete representation of the entire populous. Furthermore, we see that the Talokanil work with aquatic animals that are obviously bound to the water and are incredibly unlikely to appear in Ta Lo (should the battle take place there) while Ta Lo is full of mystical animals of Chinese legend, many of which could body a whale and barrel through any animals in Wakanda while also being fully capable of leaving the realm.
Combat-wise we know that Ta Lo’s people are capable of Wixia feats that one can compare to the fantastical style of mystic combat derived from varying Kung Fu forms that let them influence the world in a very different manner than any Earthborn is used to or really capable of combating that effectively. Wakanda of course puts up a greater fight simply because they clearly have greater technology that can apparently be produced en masse, while the Talokanil clearly hold their greatest boon in physical prowess alone.
to finalize, i place the ranking as Ta Lo, then Wakanda, then Talokan