Unfortunately if a team comes in 100k under budget the bean counters say, well obviously you didn't budget properly or you deliberately inflated your requirement, therefore we will take the 100k plus a percentage as punishment for being inefficient from next years budget. Maybe a little too cynical but you know what I mean.
Next gripe really is what effect does making 5% year on year savings through efficiencies really achieve? I suspect that there is very little fat that can be pared now without stopping the routine and mundane and essential tasks that used to be done regularly.