I am not as experienced as many here, but I have read “the encyclopedia of modern day bodybuilding” and what I remember Arnold saying is the importance of power-training in the beginning of a persons BB career. By power-training he was talking about using freeweights over machines and doing low reps. I think he recommended this form of ramping for power: 10,8,6,4,2. or something similar. For more pump he suggested 5setts ramped for reps of 10-8. But I cant remember him saying to neglect isolation movements, but rather to not neglect the big lifts.
The beginner split I think where something like this.
day1 and day4: chest and back.
day2 and day5: legs.
day3 and day6: shoulders and arms.
and I think he recommended doing calves and abs everyday.
Take this with a grain of salt thou because its over a year ago I read that book.