I would never hunt with a broadhead, that I had put into a foam target. I would change the broadhead or blades and assume the new ones should hit like the old.
You could second guess yourself to death here. But if you shoot enough of the style of broadheads that you do plan to hunt with you will (or should) see a consistancy about them.
This year I'm going with muzzy mx4's I bought 2 packs thats six actual broad heads and 2 practice broadheads. I shoot with 3 broad heads and 2 practice heads. I mix and match them on different arrows and they all hit accurately. The 3 remaining brand new ones willbe in my quiver, with confidence,opening morning.