Tiebreakers were very likely programmed into IFAs because, in the initial release, budget transfers were not allowed, and so the maximum IFA bid across all HBD was $20M (+ STI, + major league contract of $327,000 a year x 5 years; they programmed out the major league contract offer some time later).
Whether those tiebreakers are the same as for FA I don't know, but it would be my first guess.