From the Silent Hill wiki's profile on him:
Age: Around 24-26
I had always assumed him and Claudia (who was apparently 29) were solidly in their 30s. Like the dude is a priest in the Silent Hill cult's order and influential enough that he's managed to have a huge church built with money from donations
What's up with Japanese media and all these hyper-accomplished young people
It's definitely a trope, but I think it kinda works in this case.
They're not all that much older than Heather herself, who's only 17. Yet, they're more established, more decided, in a sense more "matured", and trying(in some cases, succeeding) to take those very things away from her. Her agency, her body, her guide to growing.
They're not much further physically, but they view her like a child, a vessel for their desires of the future. In doing so, it makes their downfall. She's forced to mature, and like many children with overbearing parents, that maturation pushes her against them harder and harder, culminating to the end.