Who's to say the Emperor only had one astral tadpole? It's not unreasonable that he may have been secreting a spare or two.
Often it seems like some people would prefer to find flaws. Absence of knowledge presents as certainty.
Having a convenient plot device to just pull outta one's arse with no buildup or explanation as to how it got there because it means rewriting an otherwise poorly constructed story otherwise is not a sign of a good script.
And it seems even more often that people would jump to defending something objectively bad with a lot more rabidity than when something is actually good, because something good speaks for itself instead of needing a legion of apologists...
