Catering Service Charge Breakdown

In your experience, are the caterers willing to reveal the breakdown of the “catering service charge” for transparency? I know that it goes towards the hourly wage of the staff and set up/breakdown of the venue. I know for a fact they aren’t renting their dinnerware, tables, and chairs and it’s inventoried in a separate building. There’s a separate $200/bartender fee, but the service charge is on the food AND drinks. Does that mean that part of the service charge goes to the bartenders or does it literally only go towards set up and waitstaff hourly wage? We are trying to figure out how much to tip (if any), but we also don’t want to screw the waitstaff over. I’ve estimated food and drinks based on my guest list and their food choices as well as a good estimate for alcohol. Assuming $35/hour per server at 7-8 servers, we are looking at around $500 left over on the service charge. Is that a reasonable amount for setup, breakdown, and cleaning?