You know, I sort of agree that we have no idea how this whole thing will shake out. Maybe the beginning fights are harder and it gets easier as it goes along with more people arriving to provide support and distractions. Maybe the beginning werewolf fight is easy and it gets harder as it goes on with more people coming into play bringing in more complications. I think it is kind of hard right now to predict things with the limited information available. So I'm just gonna switch to the balanced plan to try to cover all bases.
We're not running on limited information though? At least not for the first two stages. We know all the actors, we know their location in real time and we have mostly complete knowledge of two closed timeloops and therefore can plan around that. We are arguably the most informed person in this whole debacle. The
only things we know about the ending stage is that Peter is running, Snape is showing up to a scene that looks horrible and Lupin will be in play... somehow.
So first stage. We know Lupin is by himself in the forest, we know he's going to be pissed and animalistic, we know we're in a postion that he can't reach us, we also know all we have to do is get the time turner and there have been several valid ideas of how to do that. Not much room compared to the other two stages to screw that up, so it doesn't need as much allocation.
Second stage. We then have to run to the shack where the werewolf gets close to Harry, flings Sirius out of the shack and we close in and send Lupin and us to the past. At least here we have Sirius and the other three for backup (not sure how much use the kids will be but it's a distraction at the least). That's the second stage, decent info but more dangerous so we should allocate more echoes.
Then comes the third stage where we have to take on Pettigrew, a fully grown wizard, and stop him escaping, Lupin is still in play as a wild card and while Snape is on our side in terms of keeping us alive, he is against us in almost every other way. We as the voters (in general) would prefer Lupin to live, Sirius to be exonerated and Pettgrew to be dumped in Azkaban/kissed. But Snape, with his biases, is not going to want that. The man still has the largest hate boner on the planet for these three.
So in summary we have a werewolf and a fully trained wizard acting against us in our primary objective of staying alive and one of the most competent characters in the entire series working against us in our secondary objectives and absolutely no certainty of how any of them are going to act compared to the first two stages.
So that raises the question, why would we not allocate more echoes here?