500mg is the max for ace a doctor is recommended to proscribe (on it's own). 150 is well below the max for ibu. Also I think you may have mixed up the grandparent commentator that stated they were a doctor and the parent that may be a doctor but hasn't made that claim here.
200mg is normal for ibuprofen, and prescriptions for 800mg versions are not unusual.
Meanwhile 500mg is, I believe, more than they combine with opiates and acetaminophen does lead to death via organ failure on the order of hundreds of people a year. I was curious why they weighted the acetaminophen proportionally so much higher than the ibuprofen.