Torah Brachos are justified when you are making a bracha for the purpose of learning Torah. Just because one gets a Mitzvah of Talmud Torah, it's not enough for a Bracha. Even Hirhur is a mitzvah. According to the gra one can't even have hirhur without a bracha (though we don't pasken like this). Only learning with the kavana of learning justifies a bracha, not learning for a different purpose and derech agav being yotzei talmud torah.
Torah Brachos are justified when you are making a bracha for the purpose of learning Torah. Just because one gets a Mitzvah of Talmud Torah, it's not enough for a Bracha. Even Hirhur is a mitzvah. According to the gra one can't even have hirhur without a bracha (though we don't pasken like this). Only learning with the kavana of learning justifies a bracha, not learning for a different purpose and derech agav being yotzei talmud torah.
That sounds like a bit of a Brisker chakira. Is there a source for the idea that the mitzvah and the act of learning are two separate things?