Calculate new Power BI table from multiple tables using UNION, SUMMARIZE and FILTER

Question

Hi I am new to Power Bi and I am trying to generate a set of summary tables which combine data from multiple tables.

New Table= ADDCOLUMNS(
    UNION(
        SUMMARIZE(
            FILTER(
                'Purchased',
                'Purchased'[Units] > 1
            ),
            'Purchased'[Account],
            "Total Units", SUM('Purchased'[Units])
        ),
        SUMMARIZE( 
            FILTER(
                'Users',
                'Users'[Start Time].[MonthNo] = EOMONTH(TODAY(), -1)
            ),
        'Users'[Account],
        "Last Month", COUNT('Users'[Name])
        )
    ),
    "Last Month", COUNT('Users'[Name])
)

The result gives me a count of units by account, but each row is given the total of Users.

Account	Total Units	Last Month
Name 1	12	8000
Name 2	63	8000
Name 4	42	8000

How do I get the summarised result in my Last Month field?