I was not aware - until now - that Silesians were a race of dwarfs, neither did I know that fusilier caps were scaled down in size to be in proportion to their wearers.
The loyalty of the new recruits could well have been less that that of the older regiments.
The Saxon regiments taken into Prussian service in the 7YW were reorganized to the Prussian establishment as musketier regiments.
Prussian regiments Nrs 33, 35 - 49 were all fusilier regiments initially (according to Jany, Vol II); I have no idea why.