In this case you are witnesses, not parties. There is no need for you to be represented by an attorney. The Commonwealth will do all the work. If, on the other hand, you father will decide to pursue a civil case for assault, you will need a good personal injury attorney
You father as the victim does not need counsel. As to your question I'll let one of the fine lawyers from the Philly area respond to that. In the western part if the state, witnesses are not subpoenaed to criminal pretrials. If you instead mean the preliminary hearing the the subpoenas make sense. At the preliminary hearing the prosecution is reqiured to offer sufficient evid of the charged offenses to justify sending the case to the Court of Common Pleas.
Tour father is a victim and the District Attorney's Office is prosecuting the neighbor. Your father does not need an attorney in the criminal proceedings, however if he intends to file a civil claim against the perpetrator he should atleast occult with an attorney.
I agree with Mr. Jones, but I would add that to be sure about the proceeding to which you have been subpoenaed, you ought to call the office that issued the subpoena. There should be a name and address, and possibly a phone number, of the contact person to whom you can direct your questions. If you can't make contact before the date and time of the hearing, go early so you can ask whatever questions you have before the proceeding begins.
Pre-trial in Philadelphia is mostly negotiations, scheduling, and conferencing by and between attorneys. It is important to attend to help the DA prepare for his case. Your father probably does not need a lawyer. Good luck.