Unless we can talk them into fully cooperating. Storage seal(s) full of gold for the cash-up-front payment, mission terms specify low-risk rear-area support services, maybe some promises of equal shares in vaguely-defined plunder conditional on maintaining secrecy for a few days? Shouldn't be too hard for a social spec to sell that.
I'm trying to think of a way to make this work and I just don't see it. With the amount of people we need, we'd be essentially press-ganging
their entire military to go do something at our say-so. Actually, not just "something", violate AMITY, for which punishment is already their village's destruction, and do so by entering a suicidal fight against the Akatsuki!
Then, if we somehow talk them into this (we won't), they'd be traveling with us for potentially a day, a force vastly outnumbering (if perhaps not outgunning) our own, always on the verge of backstabbing us or just fleeing.
No, I don't think this is salvageable. Neither Oro nor Naruto/Tsunade would go for it.
True or not but I get the feeling that Orochimaru's
current assistants/cultists would have an idea of where said cultists are, given Orochimaru's
previous commentary on how his worshippers
would find out he killed other Orochimaru worshippers and
work harder, to the point where he apparently had to leave to get away from them. Three times.
At the very least, it's worth asking Endo; this costs us little.
Likewise, I'm trying to see if this is workable, and I don't think it is. We need hundreds of ninja, we need them quickly. These cults are certainly small and scattered all over the map; otherwise they wouldn't be "cults", they'd be known geopolitical forces on the scale of minor villages.
Actually, there's also the Efficient Ninja Hypothesis problem. If Oro's cults were this easily reachable and so numerous, wouldn't he have already thought to co-opt them for the purpose of Riftwar?
Edit:
Wait, but if this is the case (ninja we attack/capture will betray us to Akatsuki), shouldn't we also be concerned that any escapees of an assault would warn Akatsuki?
This is why we're picking our target already en-route to O'Uzu. They shouldn't know whom to warn, and by the time the news inevitably spread at ninja speeds, we should be already commencing the assault.
I understand the 'stunning' version of TLitF doesn't have long-term consequences for Mari herself, but isn't it expensive chakra-wise? Unless the targets are EJounin, normal Jounin-level genjutsu should suffice.
TLitF is unique in being a multi-target genjutsu, and Mari herself had suggested before that her main usefulness in large-scale battles would be in using TLitF to freeze "whole swathes of the battlefield" (or something along these lines).