OK... *but is the climbing or descending wing generating the most
lift?

I agree, your original question is missing some critical information.
Such as:

1. are the airspeeds the same for each aircraft?
2. confirm that the decending aircraft is not already stalled
3. Do the airplanes weigh the same?


As for your question above, given that the airplanes are ascending or
decending at constant rates then the lift is equal to the wieght of
the airplane in both cases. If the aircraft are the same wieght then
the lift generated will be the same.

Brian CFIIG/ASEL