Bisquick breakfast casserole with cooked eggs

If had that mix (cooked scrambled eggs, sausage, bacon, onion & peppers), then I would make a breakfast pot pie like this Hearty Chicken Pot Pie. I would butter the casserole dish and then layer like this.

1. The first layer would be the scrambled eggs, onions and peppers and sausage.
2. Next layer would be some shredded cheddar.
3. Now make Bisquick and pour on top
4. Lastly, I'd lay bacon over the dough

Bake it until golden brown and delicious. Since everything is really cooked safely, you are just setting the dough crust. I think you'd want to keep the crust thin and avoid a lot of dough.

If the idea is something like this breakfast casserole where the bisquick mix is mixed into raw eggs and milk, then baked, then no, this is not a good idea. Bisquick (which is basically flour, baking powder, salt, and fat) needs to be mixed into the wet ingredients, not mixed with chunks of cooked eggs.

If you're determined to get a casserole out of it, rather than just eating the leftovers, the best thing would probably be to mix the bisquick with wet ingredients (milk and additional eggs) and mix with the rest - but be aware that you're going to get something kind of strange, with chunks of egg mixed into the normal casserole.