If it just cut a part of the fletching off it should be fine. If it tore the whole thing off, then just glue another one on. If it is torn, just cut the flap off and it should still shoot fine. Lastly, if it no longer groups with the rest of the arrow, then chuck it.

It isn't terrible to sight in for broadheads and not have the bow perfectly in tune so long as the arrows are grouping well, which it seems they are. Good luck.