I need the loop to go but do not want to concatenate the two tables.
Then you're in for a lot of pain. Loops are not allowed and loosely couples tables can give inconsistent results and are bad for performance. Everything you've explained above points to concatenating the expense tables as the solution. Concatenate the tables and add a field, e.g. Source, to be able to distinguish between A and B.
Load *, 'System A' as Source
Load *, 'System B' as Source
If you still don't want to concatenate tables... well, good luck finding a solution