The Mig21 flight dynamics are modeled very well. This isn’t a Hershey bar winged aircraft , it’s stall , roll, turn characteristics ect will be different in many ways. One example is because the wing is so small you’re not going to have one wing stall before the other except in extreme yaw angles and cause you to roll over into a spin. The Mig 21 is so good take some aerodynamic courses and you’ll see it’s spot on.