Honestly? This all goes back to the fit of the pack. With a comfortable pack it is easier to carry more. The 25% rule of thumb is just that...a starting point. Best to go as light as possible; better to think of it as base weight (the weight of everything but food and water) and have a goal of keeping the base weight under 25 pounds per person. If you can, shoot for 20 pounds or less. Make sure there is no duplication (only one tent, one stove, one first aid kit, ect). Double check this, you would be surprised what you can toss out. After you get this settled, then add the food and water.

When I was a kid, I would haul on trail. So when my dad packed the backpacks, he had weight goals for mom, my sister, and himself. Everything else ... on or in my pack. I think the most he ever gave me was 80 pounds when I was 16. I was 6'5" and 175 pounds. Come to think of it, I never did grow anymore after that...