I actually like this call better vs a balanced reg > maniac.
There are actually a number of 97, 98, 910, 9J that he plays this way (though may slow w/ 97, 98, 9J on turn) and # of spade combos. It really depends how often we think he's shoving river w/ overpairs/AJ vs bluffs - I tend to think a river shove is much more weighted towards nuts/air with a balanced reg, which means we can call.
However, with a competent LAG, I wouldn't put overpairs and AJ out of his shove range necessarily. That said, if he's a true maniac and willing to triple barrel ATC, then we have to call down.
FWIW, I think 4-betting here isn't bad. It's probably the bottom end of our polarized range but I don't mind stacking off and if we know he's triple barreling a high % we put ourself in a bad spot OOP