According to the Maschinen Krieger back-story the armored fighting suits created by the Mercenary scientists and engineers were referred to as 'Peanuts' because of their thick, impenetrable shells. Subsequently the unmanned Strahl hovertanks that were designed to hunt down and destroy the A.F.S.s came to be known as 'Nutcrackers' (though due to a misunderstanding or mistranslation the Japanese authors used the word 'Nutrocker', a term which has stuck ever since).
"Originally designated 'P.K.H.103/1a & 1b' by the S.D.R. forces that used them as a stopgap measure until the P.K A. became available, the design proved unexpectedly successful on the battlefield right from the beginning and was dedicated to hunting down AFS units, which both the Shutoral and Mercenary forces called 'peanuts'. It destroyed so many 'peanuts' that it came to be called a 'nutcracker' by both friend and foe alike. Soon this nickname was adopted as it's formal name combined with it's official designation ... Nutcracker P.K.H. 103."
I think Mr. Peanut would have made a very appropriate unit insignia for the Mercenary army especially as top hats and monocles are recurring motifs in WWII nose art.
"Mr. Peanut reigns supreme in the antiques community as the first advertising icon. Introduced in 1916, the debonair marketing image of Mr. Peanut derived from a crude drawing by a Virginia schoolboy. Prompted by a nation-wide logo contest sponsored by the Planters Company, schoolboy Antonio Gentile won $5 for his design submission of Mr. Peanut. Then, a professional illustrator enhanced the youngster’s drawing adding the monocle and top hat to create the company logo that is a class above the rest."
The picture below illustrates the evolution of Mr. Peanut from his origins as a foppish dandy to the debonair gentleman we know him as today ...