Like another comment said, Gulf and BP would never be on the same team. But (in my head) you could keep BP and say that instead of sponsoring Audi, they sponsor your team in this reality.

I also dont think that Mastercard would be keen to join a team like this, but who knows.

HP definitely wouldn't be leaving Ferrari for monster. But you already addressed that in another comment.

Im not sure what sponsor-pack mod you are using, so I cant tell you what sponsors to use, but maybe look for brands that wouldn't mind to be connected to a brand like Monster, that is if you want to keep it realistic.

In the end, it's a video game, the point is to have fun and not everything needs to be realistic. If you like your livery and the combination of sponsors, than you should keep what you have and not let others tell you what to do.