Preheat the oven to 400 degrees . In a large pot, combine the stock, chicken, tomatoes and their juice, onion, chipotles and adobo sauce, 1 1/4 tsp. cumin and 2 cups water. Bring to a boil, then reduce heat to medium and simmer until the chicken is cooked through, about 20 minutes. Transfer chicken to a plate; let cool. Transfer half the soup to a blender, add the chopped tortilla and puree. Return the soup to the pot; season with salt and pepper.
Meanwhile, on a parchment-lined baking sheet, gently toss the tortilla strips with the oil. Bake, tossing halfway through cooking, until golden and crispy, about 8 minutes. Gently toss with the remaining 3/4 tsp. cumin, 3/4 tsp. salt and 1/8 tsp. pepper.
Using two forks, shred the chicken, discarding skin and bones. Add shredded meat to the pot along with the corn, 2 tsp. lime zest and 1 tbsp. lime juice; season. Divide among bowls. Top with the avocado, cilantro, radishes and baked tortilla strips.