It wasn't one or the other, it was both 30 million dead AND some unknown number of dogs killed that very likely didn't make a meaningful difference in the Soviet war effort. Congrats on getting down to the level of your enemy, I guess.
Like strapping a bomb to a dog that might very well just run off into the woods or throwing it with your arm like everyone else, right? Somehow I feel like the tank dog idea didn't come up from cutting edge military science but rather some drunken soldiers with a bomb and a stay dog and a fucked up sense of humor.
It was a serious Soviet military program. The dogs were trained to run under tanks.
A dog can run much further than a soldier can throw, which was pretty much the point. If you're close enough to throw something at an enemy tank, you are typically dead.