1st base vs 3rd base question.

Please correct me if I am wrong, but wouldn't a counting system that has a higher BE but lower PE suffer less from playing 1st base than a system that has a higher Playing efficiency?

Since the majority of gain from a system like KO is from betting and all bases have the seen the same cards by the time bets are made, it would seem that the effect would be less on KO than a system with a higher Betting efficiency.

Or am I a loon?