Least around here, utilities went with W or GE and pritmuch stayed with them. More you bought, cheaper it was. Houston and Dallas were W, possibly El Paso; Austin was GE and possibly San Antonio. Dad sold W.
In Houston the utility purchasing guy was a remote relative, who just died a couple months ago in his mid 90s within weeks of his wife. Almost certainly a fellow Mason. Then as now it was who you knew and how you knew them. I mean, a transformer is pretty much just that.