I train a running dog walk, my first running DW dog (now 8 yrs old) was consistent but would miss the odd one, probably about 4 times a year. I learnt from him and my next running DW dog is truly 100% - she never, ever misses. The DW training transferred easily for both of them to the AF, never had to teach a running AF it just happened.
Having said all that I put in a lot of training on the DW!
Sandra