different share classes trade at different prices. Employee NSO/ISO strike price at seed stage (i.e. on a SAFE) are typically priced at a FMV of 10% (!!) of the SAFE's postmoney valuation. Also, your use here of the word "fair" has triggered a personal tick of mine so I must direct you to https://quotefancy.com/quote/3709551/Chris-Voss-The-F-word-F...

Why would investors care whether a particular capital structure is "fair" to employees? As long as the company is able to recruit and retain qualified employees, any fairness or lack thereof is entirely irrelevant.

But as a potential employee interviewing for a new job, if you're being offered equity compensation then you might want to inquire about share classes and liquidation preferences. It could be a factor in your decision if you have multiple options.