@Devils Flower-
What a horrifying thing to come home to.

You have my condolences. I hope you can see justice served.
Your vet is correct - turkeys are surprisingly hardy. I strongly advise following whatever advice she gives; however, I would like to share my experience with deep wounds:
A couple years ago, I had three hens wounded by my breeding tom's spurs. Each had gashes in her side about 3/4 deep and of varying lengths. Bourbons (and possibly other breeds?) are very particualar about keeping wounds clean, and would scrape any ointment (Bag Balm, drawing salve, etc.) off within about a half hour of application. Due to the location I couldn't cover them with a wrap.
A few years back, I read an article about someone (don't remember the source) using colloidal silver ointment to treat a chicken wounded by dogs. Like your hens, she was suffered from huge wounds. I gave it a shot - applied 3x daily, it kept the wounds moist and clean enough to heal with minor scarring. I still have two of those hens (lost one to old age this year, she was six or seven IIRC) and they are as healthy as ever.
I hope your birds can heal, and wish you all the best of luck.
ETA:
Mine are dumb; getting grabbed makes them fight harder.