Yes, I agree if you load the same card to different mobile wallets, you should have a different virtual number per device. However, tapping and flipping through virtual cards on a device for multiple people is not a good idea I think (except maybe for kids, if you even have to pay for them). I find it much easier to have a tap option for each individual person (door open/door close). Also, it is much less likely you will make a mistake because you have to tap in (and sometimes tap out) consistently to have the max per day calculations work correctly.

I did not have success using the TfL website to see history for my purpose. I did not setup an account and didn't bother. It is possible a mistake was made in the calculation, but the amount of time saved in the hassle of setting up a card (I always had leftover money which wasn't easy to refund when I had to preload a card in the past) outweighed monitoring the totals based on where I tapped.

Thankfully, there are more US issuers providing tap cards, so hopefully you have enough choices to give everyone a tap card or device. I mean the same system is coming to most major US transit markets this year if not already.