A couple questions for those in the know on trip/travel insurance as it looks like Amex Platinum insurance benefits have improved in the past couple years.

1) Looking at a safari and the Amex benefits vs. using a 3rd party insurer. Looks like the biggest gap from Amex is no/limited medical coverage. What else am I missing?
2) The Amex limit is $10,000/eligible trip. This trip (for 4 people) will be more than $10,000. Is there any way around this by using 2 different Amex cards (as my wife is an AU on mine), or would that violate the terms since the trip wouldn't be booked solely on one card?