The reason I pointed to the founder's article is largely because it emphasizes that equity may be used to reward long term contribution versus relative contribution at the time the company is formed. In the context of doing what is right, it is still probably the case that 60% of the current value probably is not worth 60% of the long term value. Particularly for someone who will not be contributing long term.
Generally, the rule is to pay people in cash rather than equity if they are non-employees or not cash investors. Partially because of legal complications that come with barter, partially because amateur investors, like amateur anything, can create problems.
In the Silicon Valley investor model (as opposed to the local yokel), advisor shares are increasingly less common. The advisors come with cash and are angel investors. The reason that it is tricky and there isn't much about advisor shares is because it is not really a part of the Silicon Valley investor model. That's probably worth consideration if the business is intended to be a startup in the Silicon Valley sense rather than the buzzword for any new business including Mexican bistros, one truck lawn care services, and blogs with adword ads and Amazon affiliate links.
My bottom line advice is don't do anything tricky with equity because it will be hard to get right.