Correct, Big Blue, the Big Cheese, and Black Adam are basically tied in the strength department.
One could argue that Superman could be stronger because when he really needs to he seems able to amp his strength levels, and one could say Black Adam may be stronger because if Superman and Cap Marvel tied, and Cap Marvel is almost always not possessing the full power of Shazam (since he shares it with Mary Marvel and Cap Marvel Jr) while Black Adam on the other hand almost always has the full power of his Egyptian gods (apart from the time that he was sharing his power with Osiris), then a non-sharing Black Adam should be stronger than a sharing Captain Marvel.
However, whoever may be stronger than the other (possible, with a weighing towards a Superman who is going all out), the fact remains that they are all peers when it comes to strength. Thus they can be considered equals.
Ba wasnt in the mood to fight, and still took it to supes, by the end of the fight supes outfit was torn up and cape tattered. BA is more then a match to supes and is his peer. However when supes lost it in the end ba turned his back on him, thus supes refused to hit him from behind. If supes hit him he would have went to the moon haha. the fact that he had time to turn on supes tells me he could have moved outta the way. Supes would have never even hit him. Supes overall has the ability to over power adam under the right conditions but it will be very hard.
to my knowledge supes and ba have never beat each other.