Use your TM elsewhere.
Right now you have 2 dragonites with STAB moves. If you reroll them you could end up with HB and then what?
I'm sure you have a EQ Snorlax, or a MH Rydon, or a SE Machamp, or a NS Siczor, or a DP Lapris, or a WC Arcanine, or a FB Tyranitar that is pleading for you to use that TM on them. Help them out