[@ACHTUNG] You should really stop questioning it, seeing as Ver handed over [i]how to make the damn stuff.[/i] And people [i]can[/i] use Symphogear without Linker (that's clear from episode... 2 or 3 of GX), it just goes considerably less effectively.

Though Miku having the Shenshou Jing is AU, it's completely plausible given how GX started, and was explained when the bio was submitted. <_<