Okay, this is a question for ultralighters

If you wish to do something with the minimum possible weight, it must be because you wish something to be easy as possible.

Okay? Okay.

So now let's have a thought experiment.

Pack 1 is 36 pounds
Pack 2 is 24 pounds
Pack 3 is 12 pounds

Route A is 15 miles
Route B is 30 miles

If you were to use route A to train for route B, which would be the most effective pack to use on route A, in order to make route B easiest, assuming you can use any pack on either route?

Is there anybody here that thinks training route A with pack 1, and then doing route B with pack 3 is the wrong answer? Please explain why.