As with all conspiracies, there is always the problem that someone involved might have a shred of integrity, and will blow the whistle.
That everyone on the team is willing to keep quiet about doping "just like everyone else" is believable.
But to purposefully sabotage someone else? That's something on a very different level, and something easy enough for a sociopath, whose only concept of morality is self-serving, to justify. But it's hard to imagine how someone like that can find others to cooperate in such an endeavor. I mean, the folks working in labs are generally not so easily corruptible, I would hope. And how risky is it to fish around for someone like that?
I remain highly skeptical about how much influence Armstrong might have had in that particular area.
That said, paying off other riders' doctors, like Fuentes, to soften their programs, is within the realm of possibility.