Senki Zesshou Symphogear: Meteoroid-Falling, Burning, and Disappear, Then..., Nobunagun Recommendations
The main heroine is “dumb”. Well, dumb isn't the best way to describe them... it's more along the lines of a nativity on the part of the characters. They go about life not putting much thought into things beyond the fact they want to be friends with the people that they meet. They're hot headed and get into the middle of things without realizing it, a trait normally associated with male characters from shonen series, not female characters.
In addition to this there is the mecha gear that both girls end up having as well as the other characters with in the series. They
+These two anime have similar main characters where they are outcasts, considered weird, and are not typical "feminine" girls.
+The plot of each series are also similar because both main characters are brought into a secret defense organization created to stop an otherworldly threat.
+Both girls awaken a sleeping power that is seen as very powerful and would be a huge help to eliminating the threat once and for all.
+The abilities are also only available for use by a select few. Both main characters have a very close relationship with another girl who the main character saved at