Oh no kidding!
I was a little stronger back then, 6'1" 240.
Those arm sleeves are designed to give a little so as to simulate an arm, and not break the teeth, etc. The shepherds hit so hard, the initial strike was like a 4' long 2x4 at a moderate swing. I say this with confidence, because we had a chunk of 2x4 there to illustrate the hit
Now fill in that hit with teeth on each side with enough bite force to squeeze through the reinforced sleeve.
Then there's the second and third and fourth hit in less than 3 seconds. The shepherds tend to " chop" rapidly, not bite and hold. The speed is incredible and you are trying to anticipate it.
The only dog to draw blood was this 114 pound shep that chopped up and off the end of the sleeve onto my upper arm before I had a clue.
Now these are not your average dog by any means, and the training is effective. A person can strategize about knives and punching or kicking an attacking dog and might have some success with an untrained animal. I think most people would be amazed at how fast they are, when it is their job. Our reactions are pitiful in comparison.