Avoiding Section 105/125 discrimination by creating a new plan

[Guest ERISAQuestioner]

I was wondering if it would be possible to avoid IRC 105/125 discrimination by just creating a different plan for the highly compensated. This doesn't seem like it would work, but the sections just refer to a single plan, which suggests that you could have a different plan with different benefits. Can't different groups like collectively bargained employees have different benefits than salaried nonunion? So why can't salaried nonunion have different groups? What am I missing? Thanks in advance.