Vet L1 helps you as the Mutt won't be able to break the FT or isolate your guy in active or reactive and leave the Mutt to only one option to arm your guys. If a Mutt waits for you show up, toss some DBs and go away find a better angle and force him to choose which weapon will kill him. Drop Bears are tricky but they can be used both in active and reactive. I have some practice with them and it needed me some time to think about more than the most obvious ways to use them. Be creative, really, and toss them when you figured you're not going to win the FtF. That's better than nothing.
Even without Vet L1, the Mutt really doesn't want to Jammer your Bolts anyway when they can just chainrifle them to death, at ARM2, vs BTS6. Killing one or more Bolts is a win for the Mutt, even if they die in the process. Considering the Bolt already has access to a LSG, the only advantage of the Drop Bear in this circumstance is the Shock on the ammo. If you're in the position where the Mutt is going to chain rifle you throwing a Drop Bear is better than nothing, but you're still losing.