Reel FX, who have done the animation for films like The Book of Life, Free Birds and also animated specials and shorts is animating SCOOB, I'm not sure who is animating Smallfoot.
Using existing Warner Bros characters like Batman, Scooby Doo etc does give WAG a leg up plus from WB's POV it breathes new life into a franchise. It's the reason they're developing films based on The Flintstones, The Jetsons etc along with original ideas and adaptations like Bone.