The Jewish blessing goes far beyond a tribal blessing of those that support her.
In fact, it says that ALL the nations of the world will be blessed through her. (I paraphrase, but its accurate)
The messiah came to the jews and was later made available to the gentile world. All the people of the world are made blessed in their reception and faith in the messiah of the jews. Many christians are not supporters of the jews. They have an indifference usually based on ignorance, sometimes on learned animosity, but they are still blessed in Christ through the jewish religion.
No other tribal deity can make so grand a claim. At the least, they can not support such a grand claim.