IAG's offices are tiny - around 40 people, as I recall, to do all the group functions. Their work is also not, with that few staff, going to be proportional to the volume of business. It will be managing contract tendering, managing the managers in the group constituent companies, counting the beans, screwing up the IT some more [1], etc. - all of which continue to happen whether IAG business grows or shrinks, unless it withers away altogether.

[1] Narrator may be unreliable