那個 (that) before a noun indicates "there's a distance between you and the object"
您是不是童先生派的? (implies you are familiar with Mr. Tong)
您是不是那個童先生派的? (implies you are not familiar with Mr. Tong)
If you know Mr. Tong, you wouldn't say "That Mr. Tong"
Another example:
你聽過2025計劃嗎？ (Have you heard of Project 2025?)
你聽過那個2025計劃嗎？(Have you heard of that Project 2025?) - you are distancing yourself from Project 2025. Either you don't know much about it or you want to emphasize you are not involved in it. Similarly, saying "That Mr, Tong" puts a distance between you and him. Either you don't know him that much or you are not involved in his activate (if Mr. Tong turned out to be a con man, don't blame me for not warning you)