The problem you are encountering comes from trying to make Tableau look like excel.
Tableau treats everything uniformly. If you have grand totals for some measures, you get them for all measures. If you turn off display of a column of values, it turns off the whole column, grand totals and all. You can format the measure columns so that the data marks are colored one color (and if you select the color that is identical to the background, the numbers look invisible) and the total rows with another color (such as black), but it will do that to ALL the measure columns, not just the two you want to hide.