Nope. Because the way stats are calculated, it doesn't matter if a level 1 mild nature pokémon without Defense IVs or EVs has 1 or 49 Base Defense. Its actual stat will be 4 anyways. And because you use modifiers to lower the Defense even more, any Pokémon with a base Defense of 199 or less will have 1 as the stat used in the damage calculation. So the method you describe will result in "only" 1,082,848,464 damage, 2,165,696,892 if the mentioned symbiosis glitch is used.