Without knowing his criminal history, it's a bit difficult to predict the outcome. However, I'll do what I can with the information that you have.
Working against him is that the original offense, aggravated robbery, is obviously very serious. Also, since the violation was 5 years ago, there is an argument that he absconded (fled) from the authorities. A prosecutor would argue that he had an obligation to turn himself in when he was aware of the warrant for his arrest from the violation and that waiting 5 years was NOT the right way to address the case.
Working for him is that the sentence was rather light, this indicates to me that the facts of the case were not as egregious as the charge would indicate, and/or that he had little to no criminal history at the time. Also, it is good that he has had no trouble in 5 years. When the prosecutor argues that the 5 year period was a bad thing, the easy counter argument is that he demonstrated that he is NOT a criminal by getting in NO trouble during that 5 year period. Also, while he did not turn himself in 5 years ago, he never fled the state, he was always right there.
To answer your question, yes, I would urge him to:
If he does that, acts in a pro-active manner and turns himself in, that should go a long way towards demonstrating to the judge that he is NOT a danger to society, he is NOT the same person convicted of a very serious crime several years ago and he is NOT trying to flee from justice.
If all this happens, it is certainly possible that he would receive very little in the way of any punishment for the violation of probation.
I hope you found my answer helpful, please click on the GREEN ACCEPT for my answer. This is necessary for me to be paid for my work and so that I can get credit for assisting you. Your question will not close, and you will still have the opportunity to follow-up if needed. Leaving a bonus and positive feedback is not required, but doing so is certainly appreciated! Thank you and good luck!