Personally. back in the day when I rode herd over 15 sales people as a controller, I gave them a company credit card that THEY were responsible for paying. If the salesman wanted paid, they would turn in the expense report with documentation and I would pay every Friday. Even gave them a small travel advance to cover the lag time. Worked out well. But that was then, not now...........
Problem as I see it is that the employee may turn in five separate credit card charges on one expense report so only the summary is readily apparent which makes it difficult to balance the detail of the CC statement.
If AP codes each CC purchase to a separate line, perhaps you could create a Excel Query to pull the AP invoice detail for these transactions, then compare the purchases from the CC statement detail (downloaded into Excel).