2 firms have 2 offices, 2 sets of staff, 2 lots of overheads, 2 lots of clients, 2 administration departments, 2 secretarial pools, 2 office managers
Merge the firms and you’ve got 1 office, 1 set of staff,1 lot of overheads, 1 lot of clients, 1 administration department, 1 secretarial pool, 1 office manager
Many of your 2 sets of expenses have been reduced by … economies of scale