Correct me if I'm wrong but usually it's a more linear relationship, meaning if any 2 cards are ahead of another while HU they tend to be somewhat still ahead (against the same 2 cards) even if more people are involved. In this case the relationship b/w EV inverts, which is why I'm finding it fascinating.
Hi. This is an interesting one to think about. The linear relationship you mentioned I don't think works out when the
hands derive their strength from different sources. One of the ways to consider the difference the unknown third hand makes is to look at how the strength of the two hands are impacted, that's how it kind of makes sense to me.
At the risk of stating the obvious:
The main strength of the AQs hand is mostly making top pair if an Ace or Queen hit, with a lesser contribution from hitting the nut flush or hitting the nut straight. Those strengths hold up very well with the addition of an unknown third hand.
The main strength of the 33 hand is holding on to beat any unpaired hand. That strength is weakened considerably with the addition of another two random cards that the run out can hit.
From that perspective I think it makes sense that the value of the small pair drops off considerable more then the value of the AQs.