If Tango is anything like Rosie, he will get better as the work gets harder. Rosie blows through intro and training 1 and 2, but she was amazing for training 3 and 4 and my first level 1 test was nearly flawless.

Just don't practice your tests on him. Arabs are smart (as you probably know) and if you run through the tests too many times with him he will start to anticipate.