https://www.gov.im/media/1385016/202205_manxcare_structurechart_0824_mini-august-final-version-uploaded-050824_compressed.pdf
It would appear two out of three are being covered by Interims, Nursing & People (although the medical director position is confusing, on one slide it says interim and on others not). From the charts it doesn't show a vacant position anywhere for Quality & Safety, which is a bit worrying. Plenty of people on various quality committees but no executive director.
Will the interims be paid as if they were permanent positions? If so, then the costs for those are already included. So no saving there. If they're not being paid the full whack but are offered the positions then it's just the difference between what they're being paid now and the pay for the actual position. But it's hard to tell where those people would fit into the charts if they weren't interims.