Mormon prayer and Marian prayer

There's a striking parallel between Mormon prayer and Marian prayer. When Mormon missionaries run out of arguments, and it doesn't take long for them to bottom out, their last-ditch appeal is a challenge to pray about the truth of Mormonism:

"And when ye shall receive these things, I would exhort you that ye would ask God, the Eternal Father, in the name of Christ, if these things are not true; and if ye shall ask with a sincere heart, with real intent, having faith in Christ, he will manifest the truth of it unto you, by the power of the Holy Ghost" (Moroni 10:4).

Years ago, when I used to talk to Mormon missionaries, I'd point out that there's no reason to think the Mormon god can hear and answer prayer. In traditional Mormonism, the first god in the Mormon pantheon was a deified man. He lives on the planet Kolob. So he's a humanoid divinity who receives information through the five senses, like human beings. As such, it makes no more sense for me to pray to the Mormon god than to Zeus or Thor or Krishna. Even if they existed, they are physical beings with finite knowledge. 

Prayer has a presuppositional framework. In classical theism, God is the absolute Creator. He subsists outside of space and time. He doesn't use sensory perception as a source of information. He doesn't learn anything. Rather, he made everything–directly or indirectly. In Calvinism, God knows everything that happens because he predestines everything that happens.  

When you excise prayer from that presuppositional framework and transplant it to a pagan framework, prayer loses the metaphysical underpinnings that make it feasible. The concept of efficacious prayer doesn't exist in a metaphysical vacuum. It needs something adequate to back it up. 

Even in Catholic theology, Mary remains a human creature. It makes no more sense to direct millions of daily prayers to Mary, in scores of foreign languages, than it does to pray to Zeus, Thor, Krishna, or the Mormon god. 

Conversely, if a Catholic apologist says that despite her humanity, Mary has superhuman cognitive abilities, then why can't a Hindu or Viking or Mormon postulate the same superhuman abilities in reference to their humanoid deities?