Your saying a car with a different gear ratio ( not 1:1 ) and 45lbs tire/wheels vs 30lbs tire and wheels will not make a difference it driveline lose from transmitting power X engine power to the ground?...
The one exception is a Dynapak which attaches to the hubs of cars after you take the wheels off the car. The dyno, when set up properly compensates for the tire/wheel size and weight. The key word here is "properly".
As far as gear ratio. It is extremely misunderstood. I've already posted about this earlier this year on this forum. A properly tuned car on a properly set up dyno that simulates the road as close as possible will show approx the same HP peak numbers in every gear, but the torque peak will come on sooner and slightly higher the higher the gear as it loads up the car differently in higher gears so the VE curves shift left, same as on the street. I have a good amount of data and dyno curves from this if you wish to see it.