A number of the Japanese/Okinawan folks we trained always seemed to kinda "shorten" the words--"sko dach" rather than the "shiko-dachi" so that sounds pretty normal to me.
I know of schools that don't do the gekishi or the tensho forms at all.
I think its just a matter of personal preference.
As go the stories Miyagi taught kata based upon a given students body type and personality.
(a really big strong guy might be taught a kata to play to his strengths or perhaps one that could help him work on getting faster and more agile)
I did battle with ignorance today.......and ignorance won.