LOL, yes, at 11 months, he is just a baby, and not ready to take on a defensive/protective role.
Czech/DDR dogs mature notoriously slow. So he won't be an adult until he is 3 or 4 years old. Maybe he will be a more cautious type of dog, or he may be a different dog, with nerves of steel - give him time to grow up.
As an example, I do IPO/protection training with 1/2 Czech dog. Evem at 16 months of age, the trainer and I could see that he had a lot of potential inside, but he was still a somewhat unsure pup. Too much pressure in training, and he 'tuned out' - I let him mature at his own pace, and didn't put him to test again until he was 3 years old - very different results! No worries about his mental strenghts (not that I had any to start with).