Alright, it might take a while to get the full result and transmit it to them, but this is surely nothing worse than an SQL query where the from or to contain one of a given set of names, and the dates are within the bounds.
Are n't you making assumptions about their internal systems? These are the grown-ups.
The *bigger* problem is - who's going to sit and redact / check them all to make sure they are correct, complete and relevant? The lawyers presumably, at great expense.
Interns, and Junior partners - this is not an uncommon exercise.