Can I really not have totals on a limited data set?

I need to provide someone in my organization with a series of Top X-looks, looking at different measures. As an example let’s say customer count in top 10 countries. Doing so, I am hitting a block, as they use totals a lot, but the totals in these row limited looks do not match the data in them.

In my search I have already come across this doc but it does not give a solution to my problem, as I do not need to pivot my data at all.
I simply need to display top 10 countries, the customer count for each and a total for these 10.

And not a total for all countries in my data.

Is this really not easily achievable?

You can get the totals for your customer count with a table calculation - just sum(your_measure) and you will get a column that repeats the total on each row.

Is there any way to show this totals number in a row instead of having to show it as many times as we have rows? I already proposed this to the client, but they think it will only serve to confuse the users, if they see a column full of the same number, instead of a simple total at the bottom, as they are used to from every other system.