Even 10 seems like a far stretch given what we know. At least 99% of PLM cases only seem to involve one PL; there have definitely been some, both here and in the literature, that have seemed to feature memories from more than one distinct PL, but never more than a couple, and I'm not sure there's been one where both were verified. A case of a child remembering a PL, then living and dying, and then another child appearing who remembered being that person (and possibly the first PL in addition) would be the most concrete proof of multiple PLs, but I know of no such case from what I've seen. I certainly hope we can live as many times as we want, but evidence is sparing, so I'd deem it hypothetical for now. It's true that, in the most abstract theoretical sense, having PLM's need not necessarily correlate one-to-one with reincarnation itself, but the problem is, proposing that reincarnation without memory occurs says absolutely nothing substantive about any observable state of the world, because having no trace of a PL is exactly functionally equivalent to not having had one at all... it's a hypothesis without an observation, therefore, we may just as well suppose it doesn't happen, as it makes no difference either way.