Notsomuch a coincidence within my comic, but within pretty much all the joint projects I do with my spouse: we subconsciously fall into our favorite roles of Magic One and Stabby One. The two MCs of my comic are one example, and probably the best known, but so far, we're four-for-four, as far as I can tell.
Koreal (Wizard, his) and Adi/Saenathra (Rogue, mine)
Rook (Twilight Sorcerer, his) and Kaveri (Night thief/rogue, mine)
Anjali (No Moon Sorceress, mine) and Rachna (Scourge assassin, his)
Alaren (Wizard, his) and Ava (Mercenary, mine. Okay, technically Ava is a sorceress too, but her skills pale in comparison to Alaren's. She's much better with a sword.)