Bootsrap attack may be a common problem of all chains with finalization. Let's talk about the difficulty and the impact of launching a successful history bootsrap-poinsoning attack in our system.

First, you have to find a history point where there are enough empty accounts that had more stakes than the average total online stakes after that history point. Apparently the longer history the point is ,the more available accounts you can get. But the longer history you look back, the less impact the event of force majeure will have, which limits the history length of that point.

Second, whatever an attack aims for, the cost will not allow you to afford so many stakes.
As the example I gave, the users who sold their empty accounts to the attacker are actually risking their assets (if the attacker succeeds ,their current assets A' and B' will become useless.) for a short-term profit which is the cost of the attack. And that risk cost should not be low enough for one to bear.  At least he can't attack constantly, that makes the influence  of the bootstrap poisoning attack limited (maybe a fork with a few victims, which won't last long).