So when looking up older Scandinavian & German documents from the 15th to early 18th centuries they used "hard" C just like English and all the Romance languages do today.
This is of course because of the importance of Latin as the religious language. Eventually, all the Germanic languages began replacing "hard" C with K.
So what needs to happen in the English (& Scots) languages to follow along and replace "hard" C with K? And this literally only means "hard" C is replaced in the case this were to happen.
In German, for example, they kept C in Ch, Sch, -ck and "soft" C
(Chamäleon, Schwein, Augenblick, Balance). And only removed "hard" C (Skepiker, Musik, Klicken)
Norwegian however, took it a bit further by removing C altogether (Kameleon, Musikk, Øyeblikk, Klikk)
I think if English was to replace "hard" C they'd follow the German method mostly.
(English would likely keep Ch pronounced Sh as in Machine rather than the aforementioned examples who uses Maschine & Maskin respectively)
EDIT: I completely forgot that the Celtic languages use "hard" C.