In a large, deep skillet, heat the oil until shimmering. Season the shrimp with salt and pepper and add to the skillet. Cook over high heat until lightly browned on one side, 2 minutes. Transfer the shrimp to a plate.

Add the rice to the skillet and cook, stirring, until opaque, about 2 minutes. Stir in the tomato paste, paprika, garlic, and saffron and cook, stirring, until the rice is toasted and sizzling, about 1 minute. Add the clam broth and water and bring to a boil over high heat. Boil until the rice is still a bit crunchy and about half of the broth is absorbed, 10 minutes. Lower the heat and simmer until the rice is nearly tender and the liquid is soupy but slightly reduced, about 8 minutes. Stir in the squid, then lay the shrimp on top, cooked side up. Cover and simmer until the squid and shrimp are cooked through and the rice is tender, about 2 minutes longer.