Based on what little I know about the translation business, and abundant evidences in the show itself, the different parts of the show were scripted by different people, chopped up into fragments and outsourced to various translators - some seem to have a poor grasp on both English and Japanese. And after they stitched the show together, no one's there to do anything beyond perhaps a rudimentary check.
I mean, the "Gensokyo roams the world" "shrine maiden called Danmaku" part is only limited to that one segment of narration; other segments have another narrator, and use a different vocabulary. Some key information are repeated in different segments, and told in different ways.
The other things in the show appear stitched together too, in unexpected ways. The show contains footage from the Touhou 14 engine games, and if you care about typefaces, you'd have noticed that there are somehow three different fonts in these footage, when there really should only be one.
Meiryo
A new Japanese font first introduced in Windows Vista, this is the font Touhou 14 and 14.3 are meant to use. This font has thin strokes and round curves.
MS Gothic
The font used by pre-14 Touhou games. When run in Windows XP which does not have the Meiryo font, Touhou 14 and 14.3 will use MS Gothic instead.
ZUN's own debug version of Touhou 14 also displays MS Gothic, perhaps because it's an earlier build without the new font code.
MS Mincho
Due to problems with ZUN's font code, when run in certain non-Japanese Windows environments, all Touhou games might possibly default to the first Japanese font in the system, which is the serif font MS Mincho.
So the amazing thing is, they captured these game footages using several different computers, including one that's not even running a Japanese version of Windows.