It also seems that the actual numeric symbols .. 1, 2, 3, 4, etc all came from the Middle Eastern/Arabic mathematicians and eventually triumphed over Roman Numerals (or Egyptian symbols).
The Chinese, (the 'Far East', that is), influence shouldn't be underestimated either, (IMO). These guys were applying mathematics towards practical uses way before the rest had even figured out the basics. Y'know, one could even credit them with the honour of calling them 'Engineers' because they were so adept at applied mathematics !
I didn't catch why 'Z' is feared by mathematicians (??). It can't be Z-transforms which worry 'em … (these being the bread-and-butter of digital signal processing techniques ?)
Cheers