Well that wouldn't be the same thing since each circuit still only oversees their own chunk of the country. so a difference in rulings between circuits means you have different laws in different parts of the country.
A larger Supreme Court with several chambers would still set the standard nationwide regardless of which chamber the case goes to.
Sure there would be the issue where the outcome of your case still depends on which particular group of judges hears is. But it's not much different from what we have now where the outcome depends on which particular judge dies and which replaces him.
Just change it so that whichever particular group gets the case, the have final say and it applies throughout the nation. No whining, No appealing to a different group of supremes.